Tag Archives: astronomers

Astronomers delve into the three-dimensional makeup of the Milky Way galaxy

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Using data from the APOGEE survey, astronomers from the Potsdam Leibniz Institute for Astrophysics, the University of Vienna, and the Paris Observatory reconstructed the properties of “hidden” stars within the Milky Way’s disk.

Several real star orbits are shown on the overall starlight of the Milky Way galaxy. Image credit: S. Khoperskov / AIP.

“With each dramatic increase in the number of stars, our understanding of the Milky Way has improved,” said Dr. Sergei Khopelskov of the Potsdam Leibniz Institute for Astrophysics and his colleagues.

“From the earliest observations to increasingly advanced space and ground-based telescopes, each milestone has revealed new layers of the galaxy’s complex structure and motion.”

“Although the amount of star research continues to expand, our view of the Milky Way remains very vague because most of the stars we can study are concentrated around the Sun.”

“This discrepancy is primarily due to fundamental limitations in our observations resulting from our position in the central plane of the Milky Way’s disk.”

“At our location, the amount of stars we might be able to observe is limited by their brightness, but also by the possibility of interstellar medium blocking or dimming, called annihilation. It is affected by dust and gas.”

The authors have developed an innovative method to fill gaps in our understanding of the Milky Way’s structure.

“Rather than relying solely on observations of individual stars, we can use the entire orbits of actual stars to represent the structure and dynamics of galaxies,” they explained.

“As stars move around the center of the galaxy, they serve as a tool for mapping areas of the galaxy that our telescopes cannot directly reach, including areas on the opposite side of the Milky Way.”

“Using a model of the Milky Way’s mass distribution and observed star positions and velocities, we not only calculated the stars’ orbits, but more importantly, how much mass is associated with each orbit. I measured what I should do.”

Using a new technique, we apply it to a large sample of stars using spectroscopic parameters from the star. APOGEE surveyThis is part of the Sloan Digital Sky Survey, in which researchers mapped the kinematics of stars across the Milky Way.

They revealed the complex motion of stars within the bar region, unhindered by distance measurement uncertainties.

Astronomers quantified the galaxy’s mass-weighted chemical abundance and age structure by reconstructing the star’s orbit using real Milky Way stars with precisely determined parameters.

This approach avoids the challenges posed by dense interior regions and the disappearance of the interstellar medium, and provides a comprehensive view of the stellar population, including previously unobservable regions on the Milky Way’s far side.

“You can look at this approach from a different perspective,” Dr. Hopelskov said.

“Imagine that for every star we observe, there is a large sample of stars that follow the exact same orbits but were not captured by surveys for various reasons.”

“What we’re doing is reconstructing the positions, velocities and stellar parameters of these invisible stars and filling in the missing parts of the galaxy’s structure.”

“The new data strongly suggest that the Milky Way formed in two distinct stages, as evidenced by the different age and chemical abundance relationships.”

“The inner disk lies well inside the Sun’s radius and formed relatively quickly during the early stages of galactic evolution.”

“About 6 to 7 billion years ago, the outer disk began to assemble, rapidly expanding the radial extent of the Milky Way and forming its current structure.”

Source: www.sci.news

Astronomers Uncover Magnetic Filaments Surrounding the Central Black Hole in Messier 77’s Accretion Disk

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Messier 77 is a relatively nearby and well-known bright spiral galaxy with a supermassive black hole at its center.

Messier 77 concept by artist. It is characterized by its powerful black hole and accretion disk, as well as the polarized light of water masers located outside the Milky Way. Image credit: NSF / AUI / NRAO / S. Dagnello.

Messier 77 is a barred spiral galaxy located 62 million light-years away in the constellation Cetus.

Also known as NGC 1068, LEDA 10266, and Cetus A, it has an apparent magnitude of 9.6.

Messier 77 was discovered in 1780 by French astronomer Pierre Méchain, who initially identified it as a nebula. Méchain then relayed this discovery to his colleague, the French astronomer Charles Messier.

Messier believed that the extremely bright objects he saw were clusters of stars, but as technology advanced, their true status as a galaxy was recognized.

At 100,000 light-years in diameter, Messier 77 is one of the largest galaxies in the Messier catalog, and its gravity is enough to twist and distort other galaxies nearby.

It is also one of the closest galaxies to active galactic nuclei (AGNs).

These active galaxies are among the brightest objects in the universe, emitting light in many if not all wavelengths, from gamma rays and X-rays to microwaves and radio waves.

But Messier 77's accretion disk is hidden by a thick cloud of dust and gas, despite being a popular target for astronomers.

Several light-years in diameter, the outer accretion disk is dotted with hundreds of different water maser sources that have been hinting at deeper structures for decades.

Masers are clear beacons of electromagnetic radiation that shine at microwave or radio wavelengths. In radio astronomy, water masers, observed at a frequency of 22 GHz, are particularly useful because they can shine through many of the dusts and gases that block the wavelengths of light.

Bucknell University astronomer Jack Gallimore and his colleagues began observing Messier 77 with two goals in mind: astronomical mapping of the galaxy's radio continuum and measuring the polarization of water masers.

“Messier 77 is a bit of a VIP among active galaxies,” says Dr. CM Violette Impellizzeri, an astronomer at the Leiden Observatory.

“There's an accretion disk right next to the black hole, and it's unusually powerful. And because it's so close, it's been studied in great detail.”

But the study authors looked at Messier 77 in an entirely new way.

Their observations were recently upgraded High sensitivity array (HSA) consists of the Karl G. Jansky Very Large Array, the Very Long Baseline Array, and NSF's NRAO telescope at the Green Bank Telescope.

By measuring the water maser's polarization and the continuous radio emission from Messier 77, they reveal the compact radio source, now known as NGC 1068*, and the mysterious extended structure of the fainter emission. I created a map to

Mapping the astronomical distribution of galaxies and their water masers reveals that they are spread along structural filaments.

“These new observations reveal that the maser spot filaments are actually arranged like beads on a string,” Dr. Gallimore said.

“We were stunned to see that there was an apparent offset, or displacement angle, between the radio continuum, which describes the structure of the galaxy's core, and the position of the maser itself.”

“The configuration is unstable, so we're probably looking at a magnetically ejected source.”

Measuring the polarization of these water masers with HSA revealed significant evidence of a magnetic field.

“No one has ever seen polarization in water masers outside of our galaxy,” Dr. Gallimore said.

“Similar to the loop structures seen as prominences on the Sun's surface, the polarization patterns of these water masers clearly indicate that there is also a magnetic field at the root of these light-year-scale structures.”

“Looking at the filaments and making sure the polarization vector is perpendicular to the filaments is key to confirming that they are magnetically driven structures. It's exactly what you expected. It’s a thing.”

Previous studies of the region have suggested patterns, usually related to magnetic fields, but such conclusions were until recently beyond the scope of observational techniques.

The discovery reveals evidence for a compact central radio source (the galaxy's supermassive black hole), distinct polarization of water masers indicating structure within Messier 77's magnetic field, and spectacular extended signatures across the radio frequency continuum. It became.

Taken together, these findings indicate that magnetic fields are the underlying driving force for these phenomena.

However, many mysteries remain. For example, within the radio continuum map there is a diffuse, faint protrusion that the team has dubbed the foxtail foxtail, extending northward from the central region.

“When we set out on this, we said to ourselves, 'Let's really push the limits and see if we can get good continuum and polarization data,' and those goals were both It was a success,” Dr. Gallimore said.

“Using the NSF NRAO High Sensitivity Array, we detected the polarization of a water megamaser for the first time. We also created a very surprising continuum map, which we are still trying to understand.”

a paper The results will be explained today. Astrophysics Journal Letter.

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Jack F. Gallimore others. 2024. Discovery of polarized water vapor megamaser emission in molecular accretion disks. APJL 975, L9; doi: 10.3847/2041-8213/ad864f

Source: www.sci.news

A Giant Star’s Surface Reveals Star Spots, Observes Astronomers

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According to a team of astronomers from the Leibniz Institute for Astrophysics at the University of Potsdam, the XX triangular star, a bright K0 giant star in a binary star system located in the constellation Triangulum, exhibits chaotic, aperiodic star point behavior. That’s what it means. and Konkoli Observatory.

XX A star spot on the surface of the constellation Triangulum. Image credits: HUN-REN RCAES / Zs. Kushvari, MOME / Á. Radovani, AIP / K. Strassmeyer.

“Among the things that can be observed from a spatially resolved solar disk are the number, size and morphology of sunspots, their growth and decay, and their movement in latitude and longitude,” said lead author and director of the Leibniz Institute for Astronomy. said Professor Klaus Strassmeyer. Potsdam Astrophysics and Potsdam University, and their colleagues.

“Such spots are also seen on other stars and are called star spots.”

“We use indirect surface imaging techniques to invert the spectral line profile into an image of the stellar surface.”

“Typically we only get occasional snapshots of spots on a star’s surface, but the spots change systematically over time, and like the Sun, only then can we learn about the internal dynamos and structure of the target in question. Well known.”

“We chose the XX triangular star, one of the most speckled stars in the sky, for a more sustained application of Doppler imaging.”

XX triangle It is located about 640 light years away in the constellation Triangulum.

The star, also known as XX Tri or HD 12545, has a mass only 10% more than the Sun, a radius 10 times the Sun’s radius, and an effective temperature of 4630 K.

It has a rotation period of 24 days, which is synchronized with the orbital period of the binary star system.

XX Trigonum has previously been shown to contain a gigantic star spot with physical dimensions equivalent to 10,000 times the area of the largest group of spots ever seen on the Sun, and 10 times the size of the projected solar disk. It had been discovered in

Professor Strassmeier and his co-authors took 99 separate images of the star using an indirect surface imaging technique called Doppler imaging.

“A dark spot on the star’s surface caused its optical center (a point that essentially represents the star’s ‘center of light’) to shift by up to 24 microarcseconds, which is less than the radius of the star’s visible disk. This corresponds to approximately 10%,” they said. Said.

“These changes occur because the dark spots reduce the brightness of certain areas of the star, shifting the perceived center of light slightly.”

“However, unlike the sun’s predictable activity cycles, the displacements of these photocenters did not follow a periodic pattern. This is a largely chaotic and probably aperiodic pattern, very different from the solar dynamo. This suggests that it is a dynamo.”

“This phenomenon also highlights challenges in detecting exoplanets, as spot-induced fluctuations in the optical center can mimic or mask small movements caused by orbiting planets, which could impose substantial limitations on the detection of such exoplanets by astronomical observations.”

of findings appear in the diary nature communications.

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KG Strassmeyer others. 2024. XX Long-term Doppler images of triangular stars show chaotic aperiodic dynamos. Nat Commune 15, 9986; doi: 10.1038/s41467-024-54329-4

Source: www.sci.news

Astronomers achieve unprecedented level of detail in creating gravitational wave background map

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Astronomers using the MeerKAT Pulsar Timing Array, an international experiment using South Africa’s MeerKAT radio telescope, have discovered further evidence of gravitational wave signals originating from supermassive black hole mergers.

miles others. Created the most detailed map of gravitational waves throughout the universe to date. Image credit: Carl Knox / OzGrav / Swinburne University of Technology / South African Radio Astronomical Observatory.

“Our research opens up new avenues for understanding the universe we live in,” said astronomer Dr Matt Miles from the ARC Gravitational Wave Discovery Center (OzGRav) and Swinburne University of Technology. .

“By studying the background, we can listen to the echoes of cosmic events over billions of years. It reveals how galaxies and the universe itself have evolved over time.”

The MeerKAT Pulsar Timing Array observes and times pulsars (fast-spinning neutron stars) with nanosecond precision.

Pulsars act as natural clocks, and their steady pulses allow scientists to detect minute changes caused by passing gravitational waves.

This galaxy-scale detector provides the opportunity to map gravitational waves across the sky, revealing patterns and intensities that defy previous assumptions.

“The gravitational wave background is often thought to be uniformly distributed across the sky,” says Rowena Nathan, an astronomer at Ozgrab University and Monash University.

“The galaxy-sized telescope formed by the MeerKAT pulsar timing array allows us to map the structure of this signal with unprecedented precision, potentially revealing insights into its source.”

Astronomers have found further evidence of gravitational wave signals originating from merging supermassive black holes, capturing a signal more powerful than a similar global experiment in just one-third of the time.

“What we’re seeing suggests a much more dynamic and active Universe than we expected,” Dr. Miles said.

“We know that supermassive black holes are merging off Earth, but now we’re starting to know where they are and how many there are.”

Researchers used pulsar timing arrays to improve existing methods to build highly detailed gravitational wave maps.

This map revealed an interesting anomaly: an unexpected hotspot in the signal, suggesting a possible directional bias.

“The presence of a hotspot could point to a distinct source of gravitational waves, such as a pair of black holes billions of times more massive than the sun,” Nathan said.

“Looking at the arrangement and pattern of gravitational waves tells us how our universe exists today and contains signals from around the time of the Big Bang.”

“While there is still more work to be done to determine the significance of the hotspots we discovered, this is an exciting step forward for our field.”

“These discoveries raise exciting questions about the formation of supermassive black holes and the early history of the universe.”

“Further monitoring by the MeerKAT array could improve these gravitational wave maps and reveal new cosmic phenomena.”

“The research also has broader implications, with data that could help international scientists explore the origin and evolution of supermassive black holes, the formation of galactic structures, and even hints at early cosmic events. provided.”

The results were published in three papers. Royal Astronomical Society Monthly Notices.

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Matthew Miles others. 2024. MeerKAT Pulsar Timing Array: 4.5 Years of Data Release and Noise and Stochastic Signals in the Millisecond Pulsar Population. MNRASin press. doi: 10.1093/mnras/stae2572

Matthew Miles others. 2024. MeerKAT Pulsar Timing Array: The first search for gravitational waves with the MeerKAT radio telescope. MNRASin press. doi: 10.1093/mnras/stae2571

Kathryn Grandthal others. 2024. MeerKAT Pulsar Timing Array: Map of the gravitational wave sky with 4.5 years of data released. MNRASin press. doi: 10.1093/mnras/stae2573

Source: www.sci.news

Astronomers find scorching-hot Neptune close to TOI-3261

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Orbit of newly discovered exoplanet TOI-3261 (also known as TIC 358070912) is an inactive main sequence star located 300 parsecs (978.5 light years) away in the constellation Hydra.

Artist's concept of the super-hot Neptunian exoplanet TOI-3261b. Image credit: NASA/JPL-Caltech/K. Miller, Caltech & IPAC.

The radius of this newly discovered exoplanet, named TOI-3261b (TIC 358070912b), is 3.82 Earth's radius.

Its mass is 30.3 times that of Earth, more than twice the median mass of Neptune-sized planets in longer orbits.

To determine these properties, astronomer Emma Nabby from the University of Southern Queensland and her colleagues used data from NASA's Exoplanet Survey Satellite (TESS), the Las Cumbres Observatory's Global Telescope, and the ESPRESSO and HARPS instruments. I used

“In our measurements, TOI-3261b is exactly hot neptune desert “The planets are so rare that their rarity evokes images of desolate landscapes,” the astronomers said in a statement.

“This type of exoplanet is similar in size and composition to our own Neptune, but it orbits very close to its star.”

The planet orbits its parent star, TOI-3261, every 21 hours.

Such a narrow orbit has so far allowed the planet to belong to the same group as only three other ultrashort-period, high-temperature Neptunes: LTT-9779b, TOI-849b, and TOI-332b.

“TOI-3261b has proven to be an ideal candidate for testing new computer models of planet formation,” the researchers said.

“One reason hot Neptunes are so rare is that it's difficult to maintain a thick gaseous atmosphere in the immediate vicinity of the star.”

“Because stars are massive, they exert a large gravitational force on surrounding objects and can strip away layers of gas surrounding nearby planets.”

“It also releases a lot of energy and blows away the gas layer.”

“Both of these factors mean that a hot Neptune like TOI-3261b may have started out as a much larger Jupiter-sized planet and then lost most of its mass.”

The TOI-3261 system is about 6.5 billion years old, and the planet began as a much larger gas giant, the researchers said.

“But it likely lost mass in two ways: by photoevaporation, where energy from the star causes gas particles to dissipate, and by gravity from the star, which strips layers of gas from the planet. tidal separation,” the scientists said.

“It's also possible that the planet formed further away from the star, where both of these effects would be less strong and it would be able to maintain an atmosphere.”

“The planet's remaining atmosphere is one of its most interesting features and will likely invite further atmospheric analysis, perhaps helping to elucidate the formation history of this hot Neptunian desert dweller.”

“TOI-3261b's density is about twice that of Neptune, indicating that the lighter parts of the atmosphere have been removed over time, leaving only the heavier components,” the researchers added.

“This suggests that the planet must have started out with a variety of elements in its atmosphere, but at this stage it's difficult to know exactly what they are.”

This finding is reported in the following article: paper Published in astronomy magazine.

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Emma Naby others. 2024. Survival in the Hot Neptunian Desert: Discovery of the ultrahot Neptune TOI-3261b. A.J. 168, 132; doi: 10.3847/1538-3881/ad60be

Source: www.sci.news

Astronomers witness Jupiter’s ephemeral dark polar ellipse in ultraviolet light

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Earth-sized ovals at Jupiter's north and south poles, visible only at ultraviolet (UV) wavelengths, appear and disappear at seemingly random intervals, according to a study led by astronomers at the University of California, Berkeley.

False-color ultraviolet image of the entire planet showing a hood or cap of hydrocarbon fog covering the south pole. The edge of the arctic hood is visible at the top. Image credit: Troy Tsubota and Michael Wong, University of California, Berkeley.

Jupiter's dark ultraviolet ellipses are mostly located directly beneath bright auroral bands at each pole, similar to Earth's northern and southern lights.

This spot absorbs more ultraviolet light than the surrounding area, so it appears darker in images from the NASA/ESA Hubble Space Telescope.

In annual images of the planet taken by Hubble between 2015 and 2022, dark ultraviolet ellipses appear 75% of the time at the south pole, but only in one in eight images taken at the north pole. A dark oval will appear.

The dark ultraviolet ellipses suggest that unusual processes are occurring in Jupiter's strong magnetic field. This magnetic field propagates all the way to the poles and deep into the atmosphere, much deeper than the magnetic processes that produce auroras on Earth.

The dark ultraviolet ellipse was first detected in the 1990s by Hubble at the North and South poles, and later also at the North Pole by NASA's Cassini spacecraft, which flew close to Jupiter in 2000, but received little attention.

In a new analysis of Hubble images, University of California, Berkeley undergraduate student Troy Tsubota and his colleagues found that the oval shape is a common feature of Antarctica. They counted eight Southern Ultraviolet Dark Ovals (SUDOs) between 1994 and 2022.

In all 25 Hubble Earth maps showing Jupiter's north pole, only two northern ultraviolet dark ellipses (NUDOs) were found.

Most of the Hubble images were taken as part of the Outer Planet Atmospheres Legacy (OPAL).

“In the first two months, we realized that these OPAL images were kind of a gold mine. We quickly built this analysis pipeline and asked what we could get by sending all the images. We were able to confirm that,” says Tsubota.

“That's when we realized we could actually do good science and real data analysis and have conversations with our collaborators about why these things appear.”

The authors also aimed to determine the cause of these areas of dense fog.

They theorized that the dark ellipse was likely being stirred up from above by a vortex created when the planet's magnetic field lines rub at two very far apart locations. One is the friction in the ionosphere and the Earth's sheet, the rotational motion of which has previously been detected using ground-based telescopes. Hot ionized plasma around the planet emitted by the volcanic moon Io.

The vortex rotates fastest within the ionosphere and gradually weakens as it reaches deeper layers.

Like a tornado landing on dusty ground, the deepest parts of the vortex stir up the hazy atmosphere, creating the dense patches observed by astronomers.

It is unclear whether the mixing will dredge more haze from below or create additional haze.

Based on their observations, researchers believe that the oval shape may form over about a month and disappear within a few weeks.

Astronomer Dr Shih Zhang said: “The dark elliptical haze is 50 times thicker than typical concentrations. This is because this haze is due to the dynamics of the vortex, rather than a chemical reaction caused by high-energy particles from the upper atmosphere. This suggests that it is likely to have been formed by At the University of California, Santa Cruz.

“Our observations show that the timing and location of these high-energy particles do not correlate with the appearance of the dark ellipses.”

This discovery, which the OPAL project was designed to discover, will reveal how the atmospheric dynamics of the solar system's giant planets differ from what we know on Earth. .

“Studying the connections between different atmospheric layers is extremely important for all planets, whether exoplanets, Jupiter, or Earth,” said Dr. Michael Wong, an astronomer at the University of California, Berkeley.

“We see evidence of processes connecting everything throughout the Jovian system, from internal dynamos to satellites, plasma torii, ionospheres, and stratospheric haze.”

“Finding these examples helps us understand the entire planet.”

of study Published in a magazine natural astronomy.

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TK Tsubota others. Jupiter's ultraviolet to dark polar ellipse shows the connection between the magnetosphere and atmosphere. Nat Astronpublished online on November 26, 2024. doi: 10.1038/s41550-024-02419-0

This article is adapted from the original release by the University of California, Berkeley.

Source: www.sci.news

Astronomers reveal new main-belt comet mistaken for active asteroid

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456P/Panstars, an active main-belt asteroid first discovered in 2021, is repeatedly active, and its activity is linked to volatile ice formations, according to new observations from the Magellan-Baade and Lowell Discovery telescopes. It is likely that this is caused by sublimation.

456P/PanSTARS image taken on October 3, 2024 with the Magellan Baade Telescope in Chile and with the Lowell Discovery Telescope in Arizona on October 26, 2024. At the center of each image is the comet’s head or nucleus, the tail extends to the right. Image credits: Scott S. Sheppard / Carnegie Institution for Science / Audrey Thirouin, Lowell Observatory / Henry H. Hsieh, Planetary Science Institute.

“Main-belt comets are icy objects found in the asteroid belt between Mars and Jupiter, rather than outside the cold solar system, where icy objects would normally be expected,” said Henry Hsieh, senior scientist at the Planetary Science Institute.

“They have comet-like features, such as tails that extend away from the sun and fuzzy clouds as the sun’s heat evaporates the ice.”

These objects were first discovered in 2006 at the University of Hawaii by Dr. Hsieh and his then-doctoral supervisor, Professor David Jewitt.

“Main-belt comets belong to a larger group of Solar System objects known as active asteroids, which look like comets but have asteroid-like orbits in the warm inner Solar System,” the astronomers said.

“This large group includes not only objects that emit dust from evaporated ice, but also objects that have clouds or tails of ejected dust from collisions or rapid rotation.”

“Both main-belt comets and active asteroids in general are still relatively rare, but scientists are discovering them.”

456P/PANSTARRS was discovered as P/2021 L4 (PANSTARRS) through observations by Pan-STARRS1 on June 9 and 14, 2021, and observations by Canada, France, and Hawaii telescopes on June 14, 2021.

Dr. Hsieh and his co-authors observed the object twice in October 2024 using the Magellan-Baade Telescope and the Lowell Discovery Telescope, establishing its status as a main-belt comet.

“This object is not just an asteroid that experienced a one-off event, but is essentially an active icy object, like other comets in the outer solar system,” Hsieh said.

If 456P/PANSTARRS’s activity is due to something other than ice evaporation, its tail would be expected to appear only once, randomly, and not repeatedly as it approaches the Sun.

On the other hand, icy objects heat up every time they approach the sun, and the evaporated ice is carried away with the dust.

As the object moves away from the sun and cools, it ceases to be active.

Observations of repeated dust ejection activity during their approach to the Sun are currently considered the best and most reliable method of identifying main-belt comets.

“Confirmed main-belt comets are still largely unknown,” Dr. Xie said.

“We want to grow the population so we can understand more clearly what its broader characteristics are, such as its size, active period, and distribution within the asteroid belt. We will be able to better utilize them to track ice within the asteroid belt and across the solar system.”

of findings Published in American Astronomical Society Research Notes.

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Henry H. Shea others. 2024. Recurrence activity of main belt comet 456P/Panstars (P/2021 L4) confirmed. Resolution memo AAS 8,283;doi: 10.3847/2515-5172/ad90a6

This article is a reprint of a press release provided by the Planetary Science Institute.

Source: www.sci.news

Astronomers conduct simulations of undetected asteroids within our galaxy

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Astronomers discover large planets around other stars more often than small planets.whether to measure The gravitational pull of an exoplanet on its host starobserve How much starlight do exoplanets block?or Take a photo of the exoplanet itselfObservation methods for exoplanets are biased toward planets with masses twice the mass of Earth, or 12 septillion kilograms or more. But astronomers know that small planets exist. It's just harder to find because the smaller the planet, the more accurate equipment is needed.

Astronomers call planets smaller than Earth: sub-earth or asteroid. Current telescopes are bad at finding these tiny planets, so astronomers rely on simulations to determine how they behave. A team of astronomers studied the conditions of a hypothetical planetary system containing only asteroids. They argued that understanding where asteroids are likely to appear in large numbers will allow scientists to better understand how common these types of planets are.

To obtain a representative sample of the right conditions for planetary systems to form, astronomers simulation codeGenerate models of exoplanets similar to actual observations. Using this code, the team ran 33 sets of 1,000 simulations, each set with different starting parameters. Most stars in the Milky Way are in that size range, so they simulated a system containing stars ranging from 1/2 to 5 times the mass of the Sun. They ran all but the last two sets of simulations over a billion years of simulation time.

The first set was their point of comparison. This demonstrated that the code would produce a system containing asteroids given the same conditions as a solar system in which planets smaller than Earth are known to exist. In the next set of eight, they varied the mass of the host star, the spread of mass within the disk of matter's starting point, and the ratio of gas to dust in the system. The astronomers then ran four sets of experiments varying the period during which the asteroid could accumulate new material, ranging from 320,000 to 32 million years. The researchers ran 16 more sets, varying the amount of dust the system needed to start with, from exactly the same mass of Earth to 10,000 times the mass of Earth.

The astronomers' last four sets of simulations varied depending on the host star's mass, which ranges from 1.5 to 5 times the mass of the Sun. They ran their two largest sets on shorter timescales than the rest because large stars burn out their fuel faster and have shorter lifetimes than smaller stars. At the end of a star's life, it expands, sometimes quite dramatically. Scientists used these sets to find scenarios in which the star swallows the asteroid as it expands, and scenarios in which the star survives.

The researchers noted that computing power limits the scope of the simulation, as certain systems cannot perform calculations on more than 1,000 objects at once. Also, ice and rock were not allowed to accumulate at the edges of the system, as they do in real star systems. They said these factors limit the accuracy of models of planet formation processes and long-term system dynamics, respectively.

Overall, the research team found that asteroids should be extremely abundant in the universe. They found that under the parameters they studied, systems consisting of only planets between 1 and 110 million times the mass of Earth could “easily form.” They suggested that estimates of how often planets form around stars may significantly underestimate the actual frequency of planets.

Astronomers have found that the most important factor determining how large an asteroid becomes is the amount of dust it can initially form. But they also found that systems containing only small planets stop forming when the initial available dust exceeds 100 times the mass of Earth. Their final conclusions dealt with the outermost asteroids of certain systems, which are more than 10 times the distance from Earth to the Sun. They found that although these planets rarely grow larger than small moons, they can survive the star's inevitable expansion and persist for billions of years after the star's expansion.


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Source: sciworthy.com

Astronomers Uncover the Newest Transiting Exoplanet

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Astronomers have discovered a transiting exoplanet, named IRAS 04125+2902b, orbiting a 3 million-year-old, 0.7 solar mass protostar in the Taurus Molecular Cloud.

Artistic interpretation of the IRAS 04125+2902 system. Image credit: NASA / JPL-Caltech / R. Hurt & K. Miller, Caltech & IPAC.

The radius of IRAS 04125+2902b is 0.96 the radius of Jupiter, and the mass is

This giant exoplanet, also known as TIDYE-1b, orbits its parent star. IRAS 04125+2902once every 8.83 days.

The system is located approximately 522 light-years away in the constellation Taurus.

it is part of Taurus Molecular Cloudan active star nursery with hundreds of newborn stars.

“IRAS 04125+2902b casts doubt on previous theories about the rate of planet formation,” said astronomer Madison Barber of the University of North Carolina at Chapel Hill and colleagues.

“While Earth took 10 to 20 million years to form, this exoplanet emerged in just 3 million years and orbits its star almost every week.”

“When we discover planets like this, we can look back into the past and get a glimpse of how planets formed.”

First detected by NASA's Transiting Exoplanet Survey Satellite (TESS), IRAS 04125+2902b is the newest known transiting planet.

The discovery sheds light on potential differences between our solar system and planetary systems that host nearby giant planets, such as IRAS 04125+2902b, and provides greater context about our own cosmic neighborhood. We provide.

Additionally, because the planet is still within a disk of nascent material, scientists will be able to study its formation up close, opening up new avenues of research.

Follow-up research will analyze how the planet's atmosphere compares to the surrounding disk material, providing clues about its journey into a compressed orbit.

Astronomers will also investigate whether IRAS 04125+2902b is still growing through accretion of material, or whether it may have lost its upper atmosphere to its host star.

“Planets typically form from flat disks of dust and gas, which is why the planets in our solar system are arranged in a 'pancake-flat' arrangement,” says the Young World Institute's said lead researcher and astronomer Dr. Andrew Mann. University of North Carolina at Chapel Hill.

“But here the disk is tilted and out of alignment with both the planet and its star. This is a surprising twist that calls into question our current understanding of how planets form.”

This finding is reported in the following article: paper Published in today's magazine nature.

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MG Barber others. 2024. A giant planet passing through a 3 million meter protostar with a misaligned disk. nature 635, 574-577; doi: 10.1038/s41586-024-08123-3

Source: www.sci.news

Astronomers Find Fastest-Feeding Black Hole in Early Universe

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The 7.2 million solar mass black hole, named LID-568, appears to be feeding on matter 40 times faster than the Eddington limit and is thought to have existed just 1.5 billion years after the Big Bang.

An artist's impression of the accreting black hole LID-568 in the early universe. Image credit: NOIRLab / NSF / AURA / J. da Silva / M. Zamani.

eddington limit The maximum brightness a black hole can achieve is related to the rate at which a black hole can absorb matter, such that the inward gravitational force is balanced with the outward pressure generated from the heat of the compressed and falling matter. I will.

LID-568 appears to be feeding on matter at a rate 40 times faster than the Eddington limit.

This accreting black hole was detected by the NASA/ESA/CSA James Webb Space Telescope in a sample of galaxies from the COSMOS Legacy Survey of Chandra.

This galaxy population is very bright in the X-ray part of the spectrum, but invisible in the optical and near-infrared.

Webb's unique infrared sensitivity allows it to detect these weak corresponding emissions.

LID-568 stood out in the sample for its strong X-ray emissions, but its exact location could not be determined using X-ray observations alone.

So instead of using traditional slit spectroscopy, Webb's measurement support scientists suggested that the study authors use an integral field spectrometer. Web's NIRSpec (near infrared spectrometer) equipment.

“Due to its faint nature, detection of LID-568 would be impossible without Webb,” said Dr. Emanuele Farina, an astronomer at the International Gemini Observatory and NSF's NOIRLab.

“The use of an integral field spectrometer was innovative and necessary to obtain the observations.”

“This black hole is having a party,” said Dr. Julia Schallwechter, also of the International Gemini Observatory and NSF's NOIRLab.

“This extreme case shows that a fast-feeding mechanism that exceeds the Eddington limit is one possible explanation for why we see these extremely massive black holes in the early universe.”

These results provide new insights into the formation of supermassive black holes from smaller black hole “seeds.” Until now, theories have lacked observational support.

“The discovery of super-Eddington accretion black holes suggests that, regardless of the black hole's origin as a light or heavy seed, a significant portion of the mass growth can occur during a single episode of rapid feeding. “This suggests something,” said Dr. Hyewon Seo. Also provided by the International Gemini Observatory and NSF's NOIRLab.

“The discovery of LID-568 also shows that black holes can exceed the Eddington limit, giving astronomers the first opportunity to study how this happens,” the astronomers said. .

“The strong outflow observed on LID-568 may act as a release valve for excess energy generated by extreme accretion, preventing the system from becoming too unstable.”

“The team plans a follow-up study with Mr. Webb to further investigate the mechanisms involved.”

Their result Published in today's diary natural astronomy.

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Sue H others. A super-Eddington accretion black hole observed by JWST about 1.5 Gyr after the Big Bang. Nat Astronpublished online on November 4, 2024. doi: 10.1038/s41550-024-02402-9

This article is based on a press release provided by NSF's NOIRLab.

Source: www.sci.news

Astronomers Propose that X-ray and Ultraviolet Radiation Impact the Protoplanetary Disk in Cygnus OB2

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Cygnus OB2 is the giant young stellar association closest to the Sun.

In this new composite image, Chandra data (purple) shows the diffuse X-ray emission and young stars of Cygnus OB2, along with infrared data (red, green, blue, cyan) from NASA's now-retired Spitzer Space Telescope reveals young stars. And it creates cold dust and gas throughout the region. Image credits: NASA / CXC / SAO / Drake others. / JPL-California Institute of Technology / Spitzer / N. Walk.

At a distance of approximately 1,400 parsecs (4,600 light years), Cygnus OB2 It is a huge young body closest to the Sun.

It contains hundreds of double stars and thousands of low-mass stars.

Dr. Mario Giuseppe Guarcero of the National Institute of Astrophysics, Dr. Juan Facundo Albacete Colombo of the University of Rio Negro, and colleagues used NASA's Chandra X-ray Observatory to study various regions of Cygnus OB2. observed.

This deep observation mapped the diffuse X-ray glow between the stars and also provided an inventory of young stars within the cluster.

This inventory was combined with other inventories using optical and infrared data to create the best survey of young stars within the association.

“These dense stellar environments are home to large amounts of high-energy radiation produced by stars and planets,” the astronomers said.

“X-rays and intense ultraviolet radiation can have devastating effects on planetary disks and systems that are in the process of forming.”

The protoplanetary disk around the star naturally disappears over time. Part of the disk falls onto the star, and some is heated by X-rays and ultraviolet light from the star and evaporates in the wind.

The latter process, known as photoevaporation, typically takes 5 million to 10 million years for an average-sized star to destroy its disk.

This process could be accelerated if there is a nearby massive star that produces the most X-rays and ultraviolet light.

researchers Found Clear evidence that protoplanetary disks around stars actually die out much faster when they approach massive stars that produce large amounts of high-energy radiation.

Also, in regions where stars are more densely packed, the disk dies out faster.

In the region of Cygnus OB2, which has less high-energy radiation and fewer stars, the proportion of young stars with disks is about 40%.

In regions with higher-energy radiation and more stars, the proportion is about 18%.

The strongest influence, and therefore the worst location for a star to become a potential planetary system, is within about 1.6 light-years of the most massive star in the cluster.

In another study, the same team I looked into it Characteristics of the diffuse X-ray emission of Cygnus OB2.

They discovered that the high-energy, diffuse radiation originates from regions where winds of gas blown from massive stars collide with each other.

“This causes the gas to become hot and generate X-rays,” the researchers said.

“The low-energy release is likely caused by gas within the cluster colliding with gas surrounding the cluster.”

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MG Guarcero others. 2024. Photoevaporation and close encounters: How does the environment around Cygnus OB2 affect the evolution of the protoplanetary disk? APJS 269, 13; doi: 10.3847/1538-4365/acdd67

JF Albacete vs Colombo others. 2024. Diffuse X-ray emission in the Cygnus OB2 coalition. APJS 269, 14;doi: 10.3847/1538-4365/acdd65

Source: www.sci.news

Astronomers create a map of star formation in the heart of NGC 1386

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NGC1386 is a spiral galaxy located 53 million light years away in the constellation Eridanus.

This image of NGC 1386 combines data from VST and ALMA. Image credits: ESO / ALMA / National Astronomical Observatory of Japan / NRAO / Prieto others. / Deep investigation of Fornax.

Dr. Almudena Prieto of the Canarias Institute for Astronomy and colleagues observed the central region of NGC 1386 as part of an experiment. PARSEC projecta parsec-scale multiwavelength survey of the nearest galactic center.

“Stars often form in star clusters, which are collections of thousands of stars that originate from giant clouds of molecular gas,” the astronomers said.

“The blue ring at the center of this galaxy is ripe with star clusters filled with young stars.”

To examine this ring in more detail, Dr. Prieto and his co-authors used data from ESO's Very Large Telescope (VLT) and the NASA/ESA Hubble Space Telescope.

The data shows that these clusters all formed around the same time 4 million years ago.

“This is the first time that synchronous star formation has been observed in a galaxy containing mainly old stars,” the researchers said.

They used the Atacama Large Millimeter/Submillimeter Array (ALMA) to uncover further secrets of NGC 1386.

“The new images show numerous gas clouds as golden rings, ready to form a second wave of young stars,” the scientists said.

“But we still have to wait five million years for these to emerge.”

“Even though it is old, NGC 1386 continues to rejuvenate,” the researchers added.

of findings Published in September 2024. Royal Astronomical Society Monthly Notices.

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Almudena Prieto others. 2024. PARSEC's view of star formation at the galactic center: from primordial clusters to star clusters in early-type spirals. MNRAS 533 (1): 433-454;doi: 10.1093/mnras/stae1822

Source: www.sci.news

New Evidence of Volcanic Exomoon Found Orbiting WASP-49Ab by Astronomers

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Using the ESPRESSO instrument on ESO’s Very Large Telescope and the HARPS instrument on ESO’s La Silla 3.6-meter telescope, astronomers discovered the hot Saturn-sized gas giant exoplanet WASP-49Ab, which is close to but slightly synchronized. Detected a sodium cloud with a shifted position.

This artist’s concept depicts a volcanic exomoon that could exist between WASP-49Ab (left) and its parent star. Image credit: NASA/JPL/California Institute of Technology.

WASP-49A is a faint sun-like star discovered in 2006 by the Wide Angle Planet Survey (WASP).

The star, also known as 2MASS 06042146-1657550, is located in the constellation Lepus, about 635 light-years from Earth.

The transiting Saturn-mass companion star, WASP-49Ab (also known as WASP-49b), was discovered in 2012 in a 2.8-day orbit.

“Both WASP-49Ab and its star are composed mostly of hydrogen and helium, with trace amounts of sodium,” said Caltech astronomer Apurva Oza.

“Neither of these contain enough sodium to cause clouds, and the clouds appear to be coming from sources that are producing about 100,000 kg of sodium per second.”

“Even if stars and planets were able to produce that much sodium, it is unclear what mechanism would allow them to emit sodium into space.”

Oza and his colleagues found some evidence to suggest that the cloud was produced by another object orbiting WASP-49Ab, but additional research is needed to confirm the cloud’s behavior. .

For example, their two observations showed that when the cloud was not next to the planet, it suddenly increased in size, as if it had been refueled.

They also observed that the clouds were moving faster than the planets. This seems impossible unless the clouds are generated by another object that moves independently and faster than the planet.

“We think this is very important evidence,” Dr. Oza said.

“The cloud is moving in the opposite direction that physics tells it should go if it were part of the planet’s atmosphere.”

Astronomers have demonstrated that this cloud is located above the planet’s atmosphere, similar to the gas clouds that Io produces around Jupiter.

They also used a computer model to explain the exomoon scenario and compared it to data.

WASP-49Ab orbits the star every 2.8 days with clock-like regularity, but the cloud appears and disappears behind the star and planet at seemingly irregular intervals.

The researchers used a model to show that exomoons with eight-hour orbits around the planet sometimes appeared to move in front of the planet or did not appear to be associated with certain clouds. It was shown that it is possible to explain the movement and activity of clouds, such as how they move. region of the planet.

“The evidence that something other than a planet or star is producing this cloud is very convincing,” said Dr. Rosalie Lopez, a planetary geologist at NASA’s Jet Propulsion Laboratory.

“The detection of an exomoon is highly unusual, but thanks to Io we know that volcanic exomoons are possible.”

of findings Published in Astrophysics Journal Letter.

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Apurva V. Oza others. 2024. Redshifted sodium transient near an exoplanet transit. APJL 973, L53; doi: 10.3847/2041-8213/ad6b29

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Astronomers Discover Fewer Potentially Hazardous Asteroids Near Earth than Initially Predicted

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astronomer using Zwicky Temporary Facility (ZTF) investigated. Taurus resonance groupa large interplanetary system containing Comet 2P/Encke, several meteor showers, and possibly numerous near-Earth asteroids.

This image taken by NASA's Spitzer Space Telescope shows comet 2P/Encke running along a pebble trail of its debris. Image credit: NASA / JPL-Caltech / University of Minnesota.

“We can take advantage of the unique opportunity that this asteroid swarm has to approach Earth to more efficiently search for celestial objects that may pose a threat to Earth,” said Dr. Kuanji Ye, an astronomer at the University of Maryland. ” he said.

“Our results suggest that the risk of impact from large asteroids in the Taurus group is much lower than we thought, which is good news for planetary defense.”

Prior to this study, astronomers had predicted that the Taurus resonance complex contained a significant number of large kilometer-sized space rocks, probably left behind by large objects up to 100 kilometers (62 miles) wide. I was guessing.

If a large object were to hit Earth, like the Chelyabinsk asteroid in 2013, it could cause regional damage.

Even larger objects can cause extinction-level events, like the asteroid that wiped out the dinosaurs more than 66 million years ago.

“Fortunately, we found that there are likely only a small number of asteroids in this large size class, perhaps only nine to 14, in this population,” Dr. Ye said.

“Judging by our findings, the parent object that first spawned the swarm was probably closer to 10 km (6.2 miles) in diameter, rather than a giant 100 km diameter object.”

“We still need to be cautious about asteroid impacts, but knowing this result will probably help us sleep better.”

The Taurus swarm holds important clues about planetary evolution, especially because of its association with Comet Encke.

This comet has the shortest orbital period of any known comet, at just 3.3 years.

It is also unusually large and dusty for a short-period comet that orbits the sun within 200 years.

Considering all available evidence, scientists believe that Encke has experienced significant fragmentation in the past and may continue to do so in the future.

“Studying the Taurus swarm helps us understand how small objects like comets and asteroids form and break up over time,” said Dr. Ye.

“Our research has implications not only for asteroid detection and planetary defense, but also for our broader understanding of the solar system's celestial bodies.”

The researchers presented their findings. findings this week's DPS56Annual Meeting of the Planetary Science Division of the American Astronomical Society.

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Yosenshi others. 2024. In search of potentially dangerous asteroids in the Taurus resonance group. DPS56

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Astronomers find farthest rotating disk galaxy ever observed: REBELS-25

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According to one researcher, REBELS-25 existed until 700 million years after the Big Bang. paper Published in Royal Astronomical Society Monthly Notices.

This image shows the galaxy REBELS-25, observed by ALMA, superimposed on infrared images of other stars and galaxies. This infrared image was taken by ESO's Visible Infrared Survey Telescope for Astronomy (VISTA). Image credits: ALMA / ESO / National Astronomical Observatory of Japan / NRAO / Roland others. / Dunlop others. / Cas / Kare.

The galaxies we see today are very different from the chaotic, clumpy galaxies that astronomers typically observed in the early universe.

These messy early galaxies merge with each other and evolve into smoother shapes at an incredibly slow pace.

Current theory suggests that it would take billions of years of evolution for galaxies to become as ordered as our Milky Way, a rotating disk with an orderly structure like spiral arms.

However, the detection of REBELS-25 casts doubt on that timescale.

“Our understanding of galaxy formation predicts that most early galaxies appear small and messy,” said Dr Jacqueline Hodge, an astronomer at Leiden University.

In their study, Dr. Hodge and colleagues found that REBELS-25 existed at redshift z = 7.3 (when the universe was only 700 million years old), making it the most distant object ever discovered. They discovered that it was a strongly rotating disk galaxy.

“Seeing galaxies so similar to our own Milky Way and with strong rotational dominance adds to our understanding of how galaxies in the early universe evolved into the ordered galaxies of today's universe. It raises questions,” says Lucy Roland, a PhD student at Leiden University. University.

REBELS-25 was detected by the authors using the Atacama Large Millimeter/Submillimeter Array (ALMA).

To precisely identify the galaxy's structure and motion, they conducted follow-up observations at higher resolution with ALMA, confirming its record-breaking nature.

Surprisingly, the data suggested more developed features similar to the Milky Way, such as an elongated central bar and spiral arms, but more observations are needed to confirm this. Probably.

“Finding further evidence of a more evolved structure would be an interesting discovery, as this would be the most distant galaxy in which such a structure has been observed to date,” Rowland said.

“These future observations from REBELS-25, along with other discoveries of early rotating galaxies, could change our understanding of early galaxy formation and the evolution of the universe as a whole.”

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Lucy E. Rowland others. REBELS-25: Dynamically cold disk galaxy discovered at z = 7.31. MNRASpublished online October 7, 2024. doi: 10.1093/mnras/stae2217

Source: www.sci.news

Astronomers express worries over deployment of five new high-luminosity satellites

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AST SpaceMobile satellite illustration

AST Space Mobile

Five more are due to join the unusually reflective prototype satellites later this week, which shine brighter than nearly any star in the sky. Astronomers warn that an increasing number of bright objects in the night sky could seriously hinder their research and even limit their ability to spot asteroids heading toward Earth.

Texas-based AST SpaceMobile launched the first Blue Walker 3 satellite in 2022, but it drew immediate criticism from astronomers who discovered that the satellite was brighter than all but seven stars in the night sky.

AST SpaceMobile plans to launch a total constellation of around 100 satellites to provide mobile phone connectivity around the world. The satellites’ unusual reflectivity — much higher than most communications satellites — comes from the fact that they are equipped with a 64-square-meter reflector antenna that inadvertently acts like a mirror for visible light.

The company press release The company was scheduled to launch its first five commercial satellites, called Bluebirds, from Cape Canaveral, Florida, on September 12. The company said last year that it was exploring options to reduce its impact on astronomy, but did not respond to a request for an interview. New Scientist About the latest release.

Grant Tremblay The growing constellation of satellites in low Earth orbit “is really an existential issue for astronomy,” said the researcher at Harvard University and the Smithsonian Center for Astrophysics in Massachusetts, who is also vice president of the American Astronomical Society. AST SpaceMobile is a concern for astronomers because of its incredibly reflective design, but it’s by no means the only one, he said. Internet company Starlink is another company whose satellites are causing concern.

“In astronomy, things are clearly getting worse,” Tremblay said. “I worry that we’re in danger of losing the sky.”

Tremblay said projects such as the Vera C. Rubin Observatory, under construction in Chile and set to begin observing the sky in 2025, would see bright streaks marring images as the satellite crosses the field of view.

“If a frame is contaminated by, say, a Starlink flight, it becomes useless; it has to be thrown away,” he says. “The observatories will continue to function; great science will continue to be done. But as we start heading towards a regime with hundreds or thousands of reflective satellites of this size or larger in orbit, efficiency can fall off exponentially. We’re entering a completely unsustainable regime with no regulatory structure whatsoever.”

Tremblay sees this as a loss not just for science, but for the wider society: “We have got back this incredibly magical image of the universe on an unimaginable scale. There’s something about it that brings people together and inspires them. If we were to lose that, I think it would be a social catastrophe.”

To solve the problem, astronomers may need to place more telescopes in space beyond crowded orbits, but the cost and complexity of doing that makes that impossible in most cases, he says.

Some warn that losing our astronomical capabilities could put humanity at risk. Ian Carneri Researchers at the European Space Agency say that projects like NASA’s DART spacecraft have improved our ability over the decades to spot Earth-bound asteroids and divert them. “In the future, asteroids may become harder to find,” they say. [because of reflective satellite constellations]”That’s true,” he says.

topic:

Source: www.newscientist.com

Astronomers find breathtaking galaxy collision in ancient universe

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Using the Atacama Large Millimeter/submillimeter Array (ALMA) and the Subaru Telescope, astronomers have discovered a merging pair of gas-rich galaxies that existed 12.8 billion years ago and housed a faint central quasar that may be the ancestor of some of the brightest and most massive quasars in the early universe.

Artist's impression of the quasars HSC J121503.42-014858.7 and HSC J121503.55-014859.3. Image courtesy of Izumi others., doi:10.3847/1538-4357/ad57c6.

Quasars are luminous objects that gained energy from matter falling into supermassive black holes at the centers of galaxies in the early universe.

The most accepted theory is that when two gas-rich galaxies merge to form one larger galaxy, the gravitational interaction between the two galaxies causes gas to fall towards a supermassive black hole in one or both of the galaxies, triggering quasar activity.

To test this theory, Dr. Takuma Izumi of the National Astronomical Observatory of Japan used ALMA to study the oldest known pair of close quasars.

The quasars, named HSC J121503.42-014858.7 and HSC J121503.55-014859.3, were discovered by the Subaru Telescope's Hyper Suprime-Cam.

These objects are very faint, about 10 to 100 times fainter than highly luminous quasars at the same redshift.

“It is located approximately 12.8 billion light-years away, corresponding to the 'cosmic dawn' era when the universe was only 900 million years old, making it the farthest such quasar pair on record,” the astronomers said.

“Because of their faintness, we thought these objects were in the pre-merger stage, before the supermassive black holes rapidly grow.”

“However, observations with the Subaru Telescope only provide information about the central supermassive black hole, and it remains unclear whether the host galaxy is destined to merge and ultimately grow into a luminous quasar.”

“As a next step, we used the ALMA radio telescope to carry out observations of the host galaxies of these quasar pairs.”

“The results were surprising: the observed distribution of interstellar material and the nature of its motions indicated that these galaxies are interacting with each other.”

“They are definitely on a path to merge into one galaxy in the near future.”

“Furthermore, calculations from observational data reveal that the total gas mass of these galaxies – about 100 billion times the mass of the Sun – is comparable to or exceeds the gas mass in the host galaxies of most luminous quasars, which have extremely bright cores.”

“This enormous amount of matter should easily trigger and sustain the post-merger burst of star formation and fueling of the supermassive black hole.”

“These discoveries therefore represent a significant achievement in identifying the ancestors of luminous quasars and starburst galaxies, the most luminous objects in the early universe, from various perspectives, including galactic structure, motion and the amount of interstellar material.”

of Survey results Appears in Astrophysical Journal.

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Takuma Izumi others2024. Gas-rich galaxy merger harboring a low-luminosity twin quasar at z = 6.05: a likely progenitor of the most luminous quasars. ApJ 972, 116;doi:10.3847/1538-4357/ad57c6

Source: www.sci.news

Astronomers find a rare hot Neptune that defies convention

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The number of planets in our solar system used to be limited to only eight, excluding Pluto. These include Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune, often remembered by the phrase “My cultured mother served us nachos.” However, with the discovery of exoplanets since 1992, the list has expanded dramatically. These exoplanets, such as PSR B1257+12 b and 51 Pegasus b, have added to the existing planets, making it challenging for students to remember them all.

Scientists have observed a pattern among exoplanets concerning their masses, distances from their stars, compositions, and other factors. Interestingly, there are very few planets with masses similar to Earth and Jupiter orbiting very close to their stars, with less than 5% of Earth’s distance from the Sun.

Research indicates that the scarcity of what they call “Hot Neptunes” might be due to the evolution of large planets. As gas giants grow, they either become comparable in size to Jupiter or lose their outer gas layers, leaving behind a rocky core like Earth’s size. Furthermore, astronomers have recently discovered new exoplanets, TOI-2374 b and TOI-3071 b, in what they refer to as Neptune’s desert.

These exoplanets stand out due to their proximity to their stars, with TOI-2374 b having a mass 56 times that of Earth and TOI-3071 b being 68 times the Earth’s mass. Despite their extreme surface temperatures, the exoplanets have not evaporated, possibly due to their high metal contents.

The observations of these exoplanets provide valuable insights for future research and exploration, potentially shedding light on unexplored phenomena in Neptune’s desert.


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Source: sciworthy.com

Astronomers Spot Tiny Mark on Polaris’s Surface

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Astronomers Center for High Angular Resolution Astronomy (CHARA) Array observed Polaris, the nearest and brightest classical Cepheid star, which is part of a triple star system.

This false-color image of Polaris taken by the CHARA array in April 2021 reveals large bright and dark spots on the star's surface. Image credit: Evans others., doi:10.3847/1538-4357/ad5e7a.

PolarisCepheid variable, also known as Polaris, Polaris, Alpha Ursa Minoris, HR 424 or HD 8890, is a type of star known as Cepheid variables.

Astronomers use these stars as “standard luminaries” because their true brightness is determined by their pulsation period: brighter stars pulsate more slowly than fainter stars.

How bright a star appears in the sky depends on the star's actual brightness and its distance.

Because astronomers know a Cepheid star's true brightness based on its pulsation period, they can use it to measure the star's distance to its host galaxy and infer the universe's expansion rate.

Dr. Nancy Evans of the Harvard-Smithsonian Center for Astrophysics and her colleagues observed Polaris using the six-telescope CHARA Optical Interferometer Array on Mount Wilson in California.

Their goal was to map the orbit of a nearby, faint companion star that orbits the North Star every 30 years.

“Binary systems are extremely difficult to resolve at their closest approach due to the small distance between the two stars and the large difference in brightness,” Dr Evans said.

The researchers were able to track the orbit of Polaris's nearby companion star and measure its change in size as Polaris pulsates.

From its orbital motion, we know that Polaris has five times the mass of the Sun.

Images of Polaris reveal that its diameter is 46 times that of the Sun.

CHARA's observations also revealed for the first time what the surfaces of Cepheid variables look like.

“CHARA images revealed large bright and dark spots on Polaris' surface that change over time,” said Dr. Gail Schaefer, director of the CHARA array.

“The presence of sunspots and the rotation of the star could be related to the 120-day variation in the measured speed.”

“We plan to continue photographing the North Star,” said University of Michigan professor John Monnier.

“We hope to better understand the mechanisms that produce the spots on Polaris' surface.”

Team paper Published in Astrophysical Journal.

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Nancy Remage Evans others2024. Orbit and dynamic mass of Polaris: Observations with the CHARA array. ApJ 971, 190;doi:10.3847/1538-4357/ad5e7a

Source: www.sci.news

New pulsars discovered on Terzan 5 by astronomers

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Astronomers have discovered 10 new millisecond-plus stars in the globular cluster Terzan 5 using data from the MeerKAT radio telescope and NSF's Green Bank Telescope.

This Hubble Space Telescope image shows the star cluster Terzan 5. Image credit: F. Ferraro / NASA / ESA / ESO.

Star Cluster Terzan 5 It is a dense home to hundreds of thousands of different kinds of stars.

Also known as ESO 520-27 and 2MASX J17480455-2446441, it is located about 19,000 light-years away in the constellation Sagittarius.

“Terzan 5 is one of the most extensively studied globular clusters in history, and has produced remarkable results across multiple wavelengths,” said Scott Ransom, an astronomer at the National Radio Astronomy Observatory, and his colleagues.

“It is located in the inner bulge of the Milky Way and is thought to be the remnant of a primitive structure essential for the formation of galaxies.”

“Terzan 5 is massive (1.09 million times the mass of the Sun) and has one of the highest stellar encounter rates in globular clusters.”

“This coincides with Terzan 5 holding the record for the largest number of ms-plus stars identified in a globular cluster (39 prior to this study), with over 50% of those in binary systems (20 prior to this study).”

The ten new pulsars were discovered as part of the MeerKAT (TRAPUM) Large-Scale Survey of Transients and Pulsars project.

“It's very unusual to find a new exotic pulsar,” Dr Ransom said.

“But what's really interesting is that these strange people exist in such a diverse range of forms within one group.”

Using data from the MeerKAT telescope, the authors were able to determine the approximate location of each pulsar by tracking and measuring its rotation rate.

Archived data from the Green Bank Telescope has revealed strange and unusual details about these stars.

“Without the Green Bank Telescope archives, we would never have been able to characterize these pulsars and understand their astrophysics,” Dr Ransom said.

“This data allowed us to pinpoint the pulsar's location in the sky, measure its specific motion, and see how its orbit has changed over time.”

Among their discoveries, astronomers found two binary star systems, likely neutron stars, pulled into each other's orbit.

Of the 3,600 known pulsars in the Milky Way Galaxy, only 20 have been confirmed as double neutron star binaries.

When pulsars pair up in a binary system, the gravitational attraction of one to the other can strip matter and energy away, causing one to spin even faster and become a millisecond pulsar.

The pair is a new candidate for the fastest spinning pulsar in a double neutron star system, and has the longest orbit of its kind, potentially breaking the record.

Currently, the record holder for the fastest spinning pulsar is already held by Terzan 5.

In addition to the five binary systems already known in the cluster, the researchers also observed three unusual new pulsar “spider” binary systems.

“The discovery of these strange pulsars provides a better understanding of globular clusters and neutron stars, further tests Einstein's theory of general relativity, and expands our knowledge of the pulsar category,” the researchers said.

Their work Published in a journal Astronomy and Astrophysics.

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PV Padmanab others2024. Discovery and Timing of Ten New Millisecond Pulsars in the Globular Cluster Terzan 5. A&A 686, A166; doi: 10.1051/0004-6361/202449303

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Astronomers suggest new technological signal: silicon solar panels

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in New paper Published in Astrophysical JournalDr. Ravi Kopparapu of NASA’s Goddard Space Flight Center and colleagues assessed the detectability of silicon solar panels on Earth-like exoplanets as potential technological signatures.

Conceptual illustration of an exoplanet with an advanced extraterrestrial civilization. The structure on the right is an orbiting solar panel array that collects light from the parent star, converts it into electricity and transmits it via microwaves to the surface. The exoplanet on the left shows other potential technological features: on the night side there are city lights (the glowing circular structures), and on the day side there are multi-colored clouds representing various forms of pollution, such as nitrogen dioxide gas from the burning of fossil fuels and chlorofluorocarbons used in refrigeration. Image credit: NASA/Jay Freidlander.

“The search for extraterrestrial life has primarily focused on detecting biosignatures – remote observations of atmospheric or ground-based spectral properties that indicate signs of life on exoplanets,” said Dr Kopparapu and his co-authors.

“Recently, there has been a rise in interest in technosignatures, which refer to observational signs of extraterrestrial technology that can be detected or inferred through astronomical surveys.”

“While the search for extraterrestrial intelligence through radio observations has been popular for decades, recent studies have proposed an alternative: searching for technological signatures in the ultraviolet to mid-infrared spectral range.”

Astronomers speculate that extraterrestrials might build solar panels out of silicon because it is relatively abundant compared to other elements used in solar power generation, such as germanium, gallium, and arsenic.

Silicon is also excellent at converting light emitted by stars like the Sun into electricity, and it is cost-effective to mine and manufacture into solar cells.

The researchers also assume that a hypothetical extraterrestrial civilization would rely solely on solar energy.

However, if other energy sources, such as nuclear fusion, were used, the technological signature of silicon would be diminished, making the civilization even more difficult to detect.

Furthermore, they assume that the population of the civilization will stabilize at some point, and if for some reason this does not happen, they may end up expanding the Eternal Father into deep space.

For the study, scientists used computer models and NASA satellite data to simulate Earth-like planets with different degrees of silicon solar panel coverage.

They then modeled an advanced telescope, like NASA’s proposed Habitable Worlds Observatory, to see if it could detect the solar panels of a planet about 30 light-years away, a relatively close galaxy that is more than 100,000 light-years across.

The researchers found that hundreds of hours of observation time would be required with this type of telescope to detect signals from solar panels covering about 23% of the land area of ​​an Earth-like exoplanet.

However, the solar panel coverage needed to support 30 billion people with a high standard of living was only around 8.9%.

“We find that even if the current population of around 8 billion were to stabilise to a high standard of living of 30 billion and run solely on solar energy for power, it would still use far less energy than the total amount of sunlight illuminating the Earth,” Dr Kopparap said.

The research has implications on the Fermi Paradox, proposed by physicist Enrico Fermi, which asks why extraterrestrial civilizations have not spread across the galaxy by now, given that our own Milky Way galaxy is ancient and vast, making interstellar travel difficult but possible.

“This suggests that if a civilisation chooses a very high standard of living, it may not feel the need to expand across the galaxy because it can achieve sustainable population and energy use levels,” Dr Kopparap said.

“They may expand within their own star system, or neighboring star systems, but there may not be a galaxy-wide civilization.”

“Furthermore, our own technological expertise may not yet be able to predict what more advanced civilizations will be able to achieve.”

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Ravi Kopparap others2024. Detectability of Solar Panels as a Technology Signature. ApJ 967, 119; doi: 10.3847/1538-4357/ad43d7

This article is based on a press release provided by NASA.

Source: www.sci.news

Astronomers witness the split of dark and regular matter in the clash of two galaxy clusters

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The two galaxy clusters, known as MACS J0018.5+1626, contain thousands of galaxies each and are located billions of light-years away from Earth. As the clusters hurtled towards each other, dark matter traveled faster than normal matter.

This artist's conceptual illustration shows what happened when two massive clusters of galaxies, collectively known as MACS J0018.5+1626, collided. The dark matter (blue) in the clusters moves ahead of the associated hot gas clouds, or regular matter (orange). Both dark matter and regular matter feel the pull of gravity, but only the regular matter experiences additional effects like shocks and turbulence that slow it down during the collision. Image courtesy of W. M. Keck Observatory/Adam Makarenko.

Galaxy cluster mergers are a rich source of information for testing the astrophysics and cosmology of galaxy clusters.

However, the coalescence of clusters produces complex projection signals that are difficult to physically interpret from individual observation probes.

“Imagine a series of sand-carrying dump trucks colliding, and the dark matter would fly forward like sand,” says astronomer Emily Silich of the California Institute of Technology and the Harvard-Smithsonian Center for Astrophysics.

This separation of dark matter and normal matter has been observed before, most famously in the Bullet Cluster.

In this collision, hot gas can be clearly seen lagging behind dark matter after the two galaxy clusters push through each other.

The situation that occurred in MACS J0018.5+1626 is similar, but the direction of the merger is rotated about 90 degrees relative to the direction of the Bullet Cluster.

In other words, one of the giant galaxy clusters in MACS J0018.5+1626 is flying almost straight towards Earth, while the other is moving away.

This orientation gave the researchers a unique perspective to map the speeds of both dark and normal matter for the first time, and unravel how they separate during galaxy cluster collisions.

“Bullet Cluster makes you feel like you're sitting in the stands watching a car race, taking beautiful snapshots of cars moving from left to right on a straight stretch of road,” said Jack Sayers, a professor at the California Institute of Technology.

“For us, it's like standing in front of an oncoming car on a straight stretch of road with a radar gun and measuring its speed.”

To measure the velocity of ordinary matter, or gas, in galaxy clusters, the astronomers used an observational technique known as the kinetic Sunyaev-Zel'dovich (SZ) effect.

In 2013, they made the first observational detection of the kinetic SZ effect on an individual cosmic object, a galaxy cluster named MACS J0717.

The kinetic SZ effect occurs when photons from the early universe, or the cosmic microwave background radiation (CMB), are scattered by electrons in hot gas on their way to Earth.

Photons undergo a shift called the Doppler shift due to the movement of electrons in the gas cloud along the line of sight.

By measuring the change in brightness of the CMB due to this shift, astronomers can determine the speed of the gas clouds within the cluster.

By 2019, the study authors had made these motional SZ measurements in several galaxy clusters to determine the velocity of the gas, or ordinary matter.

They also measured the speed of galaxies within the cluster, which gave them an indirect idea of ​​the speed of dark matter.

However, at this stage of the study, our understanding of the cluster orientation was limited.

All they knew was that one of them, MACS J0018.5+1626, was showing signs of something strange going on: hot gas, or regular matter, moving in the opposite direction to dark matter.

“We saw a totally strange phenomenon where the velocities were in opposite directions, which initially made us think there might be a problem with the data,” Prof Sayers said.

“Even our colleagues simulating galaxy clusters had no idea what was going on.”

Scientists then used data from NASA's Chandra X-ray Observatory to determine the temperature and location of the gas in the cluster, as well as the extent to which it is being bombarded.

“These cluster collisions are the most energetic events since the Big Bang,” Šilić said.

“Chandra will measure the extreme temperatures of the gas, which will tell us the age of the merger and how recently the galaxy cluster collision took place.”

The authors found that before the collision, the clusters were moving towards each other at about 3,000 kilometers per second, roughly 1 percent of the speed of light.

With a more complete picture of what's going on, they were able to work out why dark matter and normal matter appear to be moving in opposite directions.

They say it's hard to visualize, but the direction of the collision, combined with the fact that dark matter and normal matter separated from each other, explains the strange speed measurements.

It is hoped that more studies like this one will be conducted in the future, providing new clues about the mysterious properties of dark matter.

“This work is a starting point for more detailed studies into the nature of dark matter,” Šilić said.

“We now have a new type of direct probe that shows us how dark matter behaves differently from ordinary matter.”

of Investigation result Published in Astrophysical Journal.

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Emily M. Silich others. 2024. ICM-SHOX. I. Methodology overview and discovery of gas-dark matter velocity separation in the MACS J0018.5+1626 merger. ApJ 968, 74; doi: 10.3847/1538-4357/ad3fb5

This article is a version of a press release provided by Caltech.

Source: www.sci.news

Astronomers suggest a new way to classify planets

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The current definition, established by the International Astronomical Union in 2006, states that to be considered a planet, an object must be in the solar system and orbit the Sun. However, this definition is problematic in that it is not quantitative and excludes exoplanets. A proposed new definition states that an object can orbit one or more stars, brown dwarfs, or stellar remnants, and sets a mass limit that should apply to any planet.

Artist's impression of an exoplanet and its host star. Image courtesy of Sci.News.

In 2006, the International Astronomical Union (IAU) adopted Resolution B5, which defines a planet as a celestial body that (a) orbits the Sun, (b) has sufficient mass so that its own gravity overcomes the forces of a rigid body, has a shape in hydrostatic equilibrium (approximately circular), and (c) is swept around its orbit.

“The current definition specifically mentions orbiting the sun,” said Professor Jean-Luc Margot of the University of California, Los Angeles.

“Thousands of planets are currently known to exist, but the IAU definition only applies to planets in our solar system.”

“We propose a new definition that can be applied to objects orbiting any star, stellar remnant, or brown dwarf.”

Prof Margot and his colleagues argue that the requirement to orbit the Sun is too specific, while other criteria in the IAU definition are too vague.

For example, it says that the planet has “gone out of orbit,” but doesn't say what that means.

The proposed new definition includes quantifiable criteria that can be applied to define planets inside and outside the solar system.

Under the new definition, a planet is (a) an object that orbits one or more stars, brown dwarfs, or stellar remnants; (b) a mass greater than or equal to 10twenty three kg, (c) is 13 times the mass of Jupiter (2.5 × 1028 kg).

The authors ran mathematical algorithms on the properties of objects in the solar system to determine which ones are densely populated.

This analysis reveals groups of distinct properties common to planets in our solar system, which can be used as a starting point for creating a general classification of planets.

For example, if an object's gravitational force is sufficient to accumulate or eject smaller objects nearby to clear a path, the object is said to be dynamically dominant.

“All planets in the solar system are dynamically dominated, but other objects, including dwarf planets like Pluto and asteroids, are not, so this property can be included in the definition of a planet,” Prof Margot said.

Dynamic dominance requirements dictate a lower mass limit.

But it's also possible that the potential planet is too large to fit the new definition.

For example, some gas giants can grow so large that thermonuclear fusion of deuterium occurs, and the object becomes a star known as a brown dwarf, no longer a planet. This limit has been determined to be more than 13 Jupiter masses.

On the other hand, the current requirement that it be spherical is more problematic.

Distant planets are rarely observed in enough detail to determine their shapes with certainty.

The researchers argue that even though planets are generally round, the shape requirements would be so difficult to implement that they are virtually useless for definitional purposes.

“Fixing the definition to mass, the quantity that is most easily measured, eliminates debate about whether a particular object meets the criteria – this is a weakness of the current definition,” said Dr Brett Gladman, a researcher at the University of British Columbia.

“The good news is that in the solar system,twenty one kg looks round.”

“Thus, any object that meets the proposed lower mass limit of 10twenty three kg is expected to be spherical.”

Team paper Published in Planetary Science Journal.

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Jean-Luc Margot othersA quantitative criterion for defining planets. Planet Science Journal 5,159; doi: 10.3847/PSJ/ad55f3

Source: www.sci.news

Astronomers Analyze Gas Flow in Uncommonly Bright Infrared Galaxy

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Ultraluminous infrared galaxies are the rarest and most extreme star-forming systems and are found only in the distant universe.

Radiative distribution of stars, cold gas, and ionized gas in the unusual HyLIRG Einstein ring PJ0116-24. Image courtesy of Liu others., doi:10.1038/s41550-024-02296-7.

“Ultraluminous Infrared Galaxies (HyLIRGs) are incredibly luminous galaxies illuminated by extremely rapid star formation within their interiors,” said Dr Daizhong Liu from the Max Planck Institute for Extraterrestrial Physics and his colleagues.

“Previous studies had suggested that such extreme galaxies must have arisen through galactic mergers.”

“The collisions of these galaxies are thought to create regions of dense gas that trigger rapid star formation.”

“However, isolated galaxies could also become HyLIRGs through internal processes alone if star-forming gas flows rapidly toward the galaxy's center.”

In the new study, the astronomers focused on a gravitationally lensed HyLIRG galaxy known as PJ0116-24.

“PJ0116-24 is so distant that it took its light about 10 billion years to reach Earth,” the researchers said.

“By chance, the foreground galaxy acts as a gravitational lens, bending and magnifying the light from the background galaxy, PJ0116-24, and directing it towards the Einstein ring.”

“This precise configuration of space allows us to magnify very distant objects and see them with a level of detail that is very difficult to achieve any other way.

The researchers used ESO's Very Large Telescope (VLT) and the Atacama Large Millimeter/submillimeter Array (ALMA) to study the motion of gas within PJ0116-24.

“ALMA tracks the cold gas which appears blue here, while the VLT with its new High Resolution Imaging Spectrograph (ERIS) tracks the warm gas which appears red,” the researchers say.

“Thanks to these detailed observations, we now know that the gas in this extreme galaxy rotates in an organized manner, rather than the chaotic state expected after a galaxy collision. A stunning result!”

“This convincingly shows that a merger is not necessarily required for a galaxy to become a HyLIRG.”

Team paper Published in the journal Natural Astronomy.

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D. Liu othersA detailed study of a rare, ultra-luminous rotating disk in a 10 billion year old Einstein ring. Nat AstronPublished online July 15, 2024; doi: 10.1038/s41550-024-02296-7

Source: www.sci.news

Astronomers find intermediate-mass black hole in largest globular cluster in Milky Way

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Using more than 500 images from the NASA/ESA Hubble Space Telescope, astronomers have found evidence of a 20,000-solar-mass black hole at the center of Earth. Omega CentauriIt is a globular cluster located in the constellation Centaurus, 5,430 parsecs (17,710 light years) from the Sun.

Omega Centauri is about 10 times more massive than other large globular clusters. Image credit: NASA / ESA / Hubble / Maximilian Häberle, MPIA.

Astronomers know that stellar-mass black holes (black holes with masses between 10 and 100 times that of the Sun) are the remnants of dying stars, and that supermassive black holes, with masses more than a million times that of the Sun, exist at the center of most galaxies.

But the universe is littered with what appear to be more mysterious types of black holes.

These intermediate-mass black holes, with masses between 100 and 10,000 times that of the Sun, are so difficult to measure that their very existence is sometimes debated.

Only a few intermediate-mass black hole candidates have been discovered so far.

Determining the black hole population is an important step towards understanding the formation of supermassive black holes in the early universe.

“Omega Centauri is a special example among globular clusters in the Milky Way,” said astronomer Maximilian Höberle of the Max Planck Institute for Astronomy and his colleagues.

“Omega Centauri is widely accepted to be the stripped core of an accreted dwarf galaxy due to its high mass, complex stellar population and kinematics.”

“These factors, combined with its proximity, make the planet a prime target in the search for intermediate-mass black holes.”

Omega Centauri is made up of about 10 million stars, making it about 10 times more massive than any other large globular cluster.

In the study, the authors measured the velocities of 1.4 million stars from images of the cluster taken by the Hubble Space Telescope.

Although most of these observations were intended for calibration of Hubble's instruments rather than for scientific use, they proved to be an ideal database for the team's research activities.

“We looked for fast-moving stars that are expected to be near concentrated masses such as black holes,” said astronomer Holger Baumgart of the University of Queensland.

“Identifying these stars was the smoking gun we needed to prove the existence of black holes, and we've done just that.”

“We found seven stars that shouldn't be there,” Dr Hebel said.

“They're moving so fast that they're likely to escape the herd and never come back.”

“The most likely explanation is that a very massive object is gravitationally tugging on these stars, keeping them near the center.”

“The only objects this massive are black holes, which have a mass at least 8,200 times that of the Sun.”

“This discovery is the most direct evidence to date for the presence of an intermediate-mass black hole at Omega Centauri,” said Dr Nadine Neumayer, an astronomer at the Max Planck Institute for Astronomy.

“This is extremely exciting because very few other black holes with similar masses are known.”

“The black hole at Omega Centauri may be the best example of an intermediate-mass black hole in our cosmic neighborhood.”

Team paper Published in the journal Nature.

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M. Heberle others2024. Stars moving at high speed around the intermediate-mass black hole at Omega Centauri. Nature 631, 285-288; Source: 10.1038/s41586-024-07511-z

Source: www.sci.news

Astronomers Decode the Calendar Ring of the Antikythera Mechanism

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The Antikythera Mechanism is a multi-part device recovered from a shipwreck near the Greek island of Antikythera in 1901. It is believed to be the remains of a complex mechanical calculator from ancient times and has undergone considerable scrutiny and analysis to determine its true form and function. In a new study, astronomers from the University of Glasgow have used statistical modelling techniques developed to analyse gravitational waves to identify the location of a hole under the Antikythera Mechanism's calendar ring. Their results provide new evidence that the component was likely used to track the Greek lunar calendar.

Fragment of the Antikythera Mechanism. Image credit: National Archaeological Museum of Athens / CC BY-SA 3.0.

The Antikythera shipwreck is a Roman shipwreck dating back to the 1st century BC (85-50 BC).

It is located at the junction of the Aegean and Mediterranean Seas, east of the Greek island of Antikythera, near Crete.

The Antikythera ships are thought to have been carrying looted treasure from the coast of Asia Minor to Rome in support of a planned triumphal parade for Julius Caesar.

The wreck was discovered in 1900 by a group of Greek sponge diggers on their way to Tunisia, who had taken refuge from a storm near the island and decided to look for sponges while waiting for calmer weather.

Early excavations at the site produced a wealth of finds that are today housed in the National Archaeological Museum in Athens, Greece, including three life-size marble horses, jewels, coins, glassware, and hundreds of works of art, including a statue of Hercules.

The most surprising find was the corroded remains of a complex device known as the Antikythera Mechanism, which is thought to have been an early analog computer used to plan important events such as religious ceremonies, the early Olympic Games and agricultural activities.

Also known as the first mechanical computer, this bronze device was created between 150 and 100 B.C.

It was originally housed in a wooden case with overall dimensions of 31.5 x 19 x 10 cm, with doors at the front and back and much of the exterior covered with astronomical inscriptions.

The surviving fragments contain 30 gears in an incredibly complex arrangement – technological artifacts of similar complexity would not appear until 1,000 years later.

In 2020, new X-ray images of one of the rings in the mechanism, known as the calendar ring, revealed new details about the regular rows of holes underneath the ring.

However, because the ring was broken and incomplete, it was unclear how many holes it originally had.

Initial analysis by Antikythera researcher Chris Budicelic and his colleagues suggests it probably dates to between 347 and 367 B.C.

Above: The 82 surviving fragments of the Antikythera Mechanism. Image courtesy of T. Freeth others2006. Below: Reconstruction of the Antikythera Mechanism by Alan Bromley and Frank Percival. Image courtesy of Alan Bromley.

In the new study, University of Glasgow researchers Graham Warne and Joseph Bayley used two statistical analysis methods to uncover new details about the calendar wheel.

The study found that it was far more likely that the ring had 354 holes corresponding to the lunar calendar, rather than 365 holes according to the Egyptian calendar.

The analysis also shows that the presence of 354 holes is hundreds of times more likely than a ring with 360 holes, which previous studies have suggested as a possible number.

“Late last year a colleague pointed me to some data available from YouTuber Chris Budiselic, who was trying to make a replica calendar ring and was researching ways to work out how many holes there are in the ring,” Prof Warne said.

“I thought this was an interesting problem and thought there might be a different way to solve it over the Christmas holidays, so I set out to answer the question using statistical methods.”

Using a technique called Bayesian analysis, which uses probability to quantify uncertainty based on incomplete data, Professor Warne used the positions of the remaining holes and the arrangement of the ring's six remaining fragments to calculate an estimated number of holes in the mechanism.

His findings provided strong evidence that the mechanism's calendar ring contained either 354 or 355 holes.

At the same time, Dr Bailey had also heard about the problem, and he was applying techniques used by his group to probe the calendar ring by analysing signals picked up by the LIGO gravitational wave detectors, which measure tiny ripples in space-time caused by massive astronomical events such as colliding black holes passing through Earth.

The Markov Chain Monte Carlo and nested sampling methods used by Professor Warne and Dr Bailey provided a comprehensive set of probabilistic results, again suggesting that the ring most likely contained 354 or 355 holes within a circle of radius 77.1mm, with an uncertainty of approximately 1/3mm.

They also found that the holes were precisely positioned with exceptional precision, with the average radius variation between each hole being just 0.028mm.

“Previous studies had suggested that the calendar ring was likely lunar based, but the dual techniques we applied in this study make it much more likely that this was the case,” Dr Bailey said.

“It gave me a new appreciation for the Antikythera Mechanism and the effort and care that Greek artisans put into creating it. Getting the holes exactly where they were would have required extremely precise measuring techniques and an incredibly steady hand to drill them.”

“This is a fascinating symmetry that allows us to apply techniques used to study the universe today to better understand the mechanisms that helped people around 2,000 years ago to understand the movements of celestial bodies,” Prof Warne said.

“While our discoveries about the Antikythera Mechanism are not as supernaturally spectacular as the Indiana Jones mechanism, we hope they will help us better understand how this incredible device was built and used by the Greeks.”

a paper A paper on the findings was published in the July 2024 issue. Watch Journal.

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Graham Warne & Joseph Baillie. 2024. The number of holes in the Antikythera Mechanism’s improved calendar ring: a new analysis. Watch Journal

This article has been adapted from an original release from the University of Glasgow.

Source: www.sci.news

Astronomers Witness Starburst Galaxy NGC 4449 in Action

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Astronomers using the International Gemini Observatory’s Gemini North Telescope have imaged NGC 4449, a prime example of starburst activity caused by an ongoing merger with a nearby dwarf galaxy.

NGC 4449 is located in the constellation Canes Venatici and is about 12.5 million light-years away from Earth.

Also known as Caldwell 21, LEDA 40973, and UGC 7592, the galaxy has a diameter of about 20,000 light-years.

NGC 4449 was discovered on April 27, 1788, by German-born British astronomer William Herschel.

It is part of the M94 galaxy group, located near the Local Group, which contains our own Milky Way galaxy.

“The galaxy’s rolling red clouds and glowing blue veil light up the sky with the color of newly forming stars,” the astronomers said.

“The galaxy is classified as an Irregular Magellanic Galaxy, reflecting its loose spiral structure and similarity to the Large Magellanic Cloud, the prototype of the Magellanic Cloud.”

Stars have been forming actively within NGC 4449 for billions of years, but new stars are currently being produced at a much higher rate than in the past.

This unusually explosive and intense star formation activity qualifies this galaxy to be called a starburst galaxy.

“While starbursts typically occur in the centers of galaxies, star formation in NGC 4449 is more widespread, as evidenced by the fact that the youngest stars are found both in the galaxy’s central core and in the outflow that surrounds the galaxy,” the researchers said.

“This global starburst activity resembles the earliest star-forming galaxies in the universe, which grew by merging and agglomerating with smaller stellar systems.”

“And like its galactic progenitors, NGC 4449’s rapid star formation is likely driven by interactions with nearby galaxies.”

A member of the M94 galaxy group, NGC 4449 sits very close to several smaller galaxies around it.

Astronomers have found evidence of interactions between NGC 4449 and at least two other satellite galaxies.

One is a very faint dwarf galaxy that is actively absorbing, as evidenced by the diffuse streaming of stars on one side of NGC 4449.

“This stealthy merger is nearly undetectable by visual inspection due to its diffuse nature and low stellar mass,” the scientists said.

“But this galaxy harbors a huge amount of dark matter, and we can detect its presence through its large gravitational influence on NGC 4449.”

“Another object that offers a clue to past mergers is a massive globular cluster embedded within the outer halo of NGC 4449.”

Astronomers believe the cluster is the surviving core of a former gas-rich satellite galaxy that is now being absorbed into NGC 4449.

“As NGC 4449 interacts with and absorbs other, smaller galaxies, the gas is compressed and shocked by tidal interactions between the galaxies,” the astronomers said.

“Red glowing regions scattered throughout the image indicate this process, showing an abundance of ionized hydrogen, a clear sign of ongoing star formation.”

“Dark filaments of cosmic dust that thread their way throughout the Galaxy are causing countless hot, young, blue star clusters to emerge from the galactic oven.”

“At the current rate, NGC 4449’s supply of gas to support star formation will last only another billion years or so.”

Source: www.sci.news

Astronomers find the farthest merging quasar pair ever recorded

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Astronomers have discovered a pair of merging quasars observed just 900 million years after the Big Bang. Not only is this the most distant pair of merging quasars ever found, but it’s also the first pair identified during a period in the history of the universe known as the “cosmic dawn.”

This image taken with the Subaru Telescope’s HyperSupreme-Cam shows a pair of quasars in the process of merging, HSC J121503.42-014858.7 (C1) and HSC J121503.55-014859.3 (C2). Image courtesy NOIRLab / NSF / AURA / TA Rector, University of Alaska Anchorage & NSF NOIRLab / D. de Martin, NSF NOIRLab / M. Zamani, NSF NOIRLab.

The dawn of the universe lasted from about 50 million to 1 billion years after the Big Bang.

During this period the first stars and galaxies began to appear and the dark universe was filled with light for the first time.

The appearance of the first stars and galaxies marked the beginning of a new era in the formation of the universe, known as the Reionization Epoch.

The epoch of reionization that occurred during the cosmic dawn was a period of cosmic transition.

About 400 million years after the Big Bang, ultraviolet light from the first stars, galaxies, and quasars spread throughout the universe, interacting with intergalactic matter and beginning a process called ionization, which stripped electrons from the universe’s primordial hydrogen atoms.

The reionization epoch is a crucial period in the history of the universe, marking the end of the cosmic dark ages and sowing the seeds of the large structures we observe in the local universe today.

To understand exactly what role quasars played during the reionization period, astronomers are interested in discovering and studying quasars that existed during this earlier, distant era.

“The statistical properties of quasars during the reionization stage can tell us a lot, including the progress and origin of reionization, the formation of supermassive black holes at the dawn of the universe, and the earliest evolution of the quasars’ host galaxies,” said Dr Yoshiki Matsuoka, an astronomer at Ehime University.

About 300 quasars have been discovered during the reionization period, but none have been found in pairs.

But as Dr. Matsuoka and his team were reviewing images taken with the Subaru Telescope’s HyperSupreme-Cam, a faint red spot caught their eye.

“While screening images for potential quasars, we noticed two similar, very red sources next to each other. This discovery was pure coincidence,” Dr Matsuoka said.

The distant quasar candidates are contaminated by many other sources, including foreground stars and galaxies and gravitational lensing, so the authors were unsure whether they were quasar pairs.

To confirm the nature of these objects, named HSC J121503.42-014858.7 and HSC J121503.55-014859.3, the team carried out follow-up spectroscopic measurements using the Faint Object Camera and Spectrograph (FOCAS) on the Subaru Telescope and the Gemini Near-Infrared Spectrograph (GNIRS) on the Gemini North Telescope.

The spectra obtained by GNIRS resolved the light emitted by the source into its constituent wavelengths and were crucial for characterizing the properties of the quasar pair and its host galaxy.

“GNIRS observations have shown that quasars are too faint to be detected in near-infrared light, even with the largest ground-based telescopes,” said Dr Matsuoka.

This allowed astronomers to deduce that some of the light detected in the visible wavelength range comes not from the quasar itself, but from ongoing star formation in its host galaxy.

The two black holes were also found to be enormous, with masses 100 million times that of the Sun.

This, combined with the presence of a bridge of gas extending between the two quasars, suggests that the two quasars and their host galaxies are undergoing a major merger.

“The existence of merging quasars during the reionization period has long been predicted, but this has now been confirmed for the first time,” said Dr Matsuoka.

This discovery paper In Astrophysical Journal Letters.

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Yoshiki Matsuoka others2024. Discovery of twin quasars merging at z = 6.05. Apu JL 965, L4; doi: 10.3847/2041-8213/ad35c7

Source: www.sci.news

Astronomers observe the reawakening of a supermassive black hole

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In December 2019, a little-known galaxy called SDSS 1335+0728, located 300 million light-years away in the constellation Virgo, suddenly started glowing brighter than ever before. To understand why, astronomers used data from multiple space and ground-based observatories to track the changes in the galaxy's brightness. They concluded that they were witnessing the sudden awakening of the supermassive black hole at its center.

This artist's impression shows the black hole drawing in the surrounding gas, growing a disk of material that lights up the galaxy. Image credit: ESO/M. Kornmesser.

“Imagine observing a distant galaxy for years and it always seemed quiet and inactive,” said Dr Paula Sánchez Sáez, astronomer at ESO and the Millennium Astrophysics Institute.

“Suddenly, the brightness of its central core began to change dramatically, which is not a typical phenomenon we've seen before.”

This is what happened to SDSS 1335+0728, which has been classified as having an active galactic nucleus (AGN) after brightening dramatically in December 2019.

Galaxies can suddenly brighten due to events such as supernova explosions or tidal disruption, but these changes in brightness usually only last for a few tens or, at most, a few hundred days.

SDSS 1335+0728 continues to grow brighter, more than four years after it was first observed “lighting up.”

What's more, the changes detected in the galaxy are unlike anything seen before, suggesting alternative explanations to astronomers.

Dr Sáez and his colleagues sought to understand these brightness changes by combining archival data with new observations from several facilities, including the X-SHOOTER instrument on ESO's Very Large Telescope.

Comparing data taken before and after December 2019, we found that SDSS 1335+0728 now emits much more light in ultraviolet, visible and infrared wavelengths, and the galaxy also began emitting X-rays in February 2024.

“This kind of action is unprecedented,” Dr. Saez said.

“The most concrete option to explain this phenomenon is that we are seeing the galactic core starting to show activity,” added Dr Lorena Hernández García, an astronomer at the Millennium Institute for Astrophysics and Valparaíso University.

“If this is the case, it would be the first time that we have observed the activation of a massive black hole in real time.”

“Supermassive black holes are normally dormant and cannot be seen directly,” said Dr Claudio Ricci, an astronomer at the Diego Portales University and the Kavli Institute for Astronomy and Astrophysics at Peking University.

“In the case of SDSS 1335+0728, we were able to observe a massive black hole awakening and suddenly absorbing the surrounding gas, becoming extremely bright.”

“This process has never been observed before,” Dr. Garcia said.

“Previous studies have reported that dormant galaxies become active after a few years, but this is the first time that the process of black hole awakening itself has been observed in real time.”

“This could also happen to Sagittarius A*, the supermassive black hole at the centre of our Milky Way galaxy, but we don't know how likely this is to happen.”

“Regardless of the nature of the fluctuations, SDSS 1335+0728 will provide valuable information about how black holes grow and evolve,” said Dr. Sáez.

“We hope that instruments like MUSE on the VLT and the upcoming MUSE on the Extremely Large Telescope (ELT) will hold the key to understanding why galaxies are brightening.”

of study Published in a journal Astronomy and Astrophysics.

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P. Sanchez Aes others2024 SDSS1335+0728: The awakening of the universe about 1 billion years ago6 M_sun Black hole. A&Ain press; doi: 10.1051/0004-6361/202347957

Source: www.sci.news

Astronomers say that a near, warm Neptune has a sulfurous atmosphere

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The warm Neptunian exoplanet, called GJ 3470b (Gliese 3470b), is 96 light years away and orbits a 2 billion year old red dwarf star in the direction of the constellation Cancer.

Artist's impression of the warm-Neptunian exoplanet GJ 3470b. Image courtesy of the University of Wisconsin-Madison Department of Astronomy.

First discovered in 2012, GJ 3470b is the lightest and coolest (over 325 degrees Celsius, or 600 degrees Fahrenheit) exoplanet containing sulfur dioxide.

The compounds are likely a sign of active chemistry taking place in the planet's atmosphere, as radiation from a nearby star explosively breaks down hydrogen sulfide components, which then seek out new molecular partners.

“We never expected to see sulfur dioxide on such a small planet, so finding this new molecule in an unexpected place is exciting because it gives us new ways to understand how these planets formed,” said Professor Thomas Beatty of the University of Wisconsin-Madison.

“And small planets are particularly interesting because their composition depends heavily on how the planet-formation process happened.”

Prof Beatty and his colleagues hope that by observing what exoplanets contain, they can shed light on the principles of planet formation and do just that.

“The discovery of sulphur dioxide on a small planet like GJ 3470b adds another important item to the list of ingredients for planet formation,” Prof Beatty said.

In the case of the GJ 3470b, there are also other interesting features that could help round out that recipe.

The planet orbits the star and passes nearly over the star's pole, meaning that it orbits at a 90 degree angle to the expected orbit of a planet in this system.

The moon is also incredibly close to its star, close enough that light from the star would blow a lot of GJ 3470b's atmosphere out into space.

The team says the planet may have lost around 40% of its mass since it formed.

The misaligned orbit suggests that GJ 3470b was once somewhere else in the system, and at some point, the planet became caught in the gravity of another planet, pulling it into a new orbit and eventually settling in a different neighborhood.

“The migration history that led to this polar orbit and how it has lost so much mass are things we don't typically know about other exoplanet targets that we study,” Prof Beattie said.

“These are important steps in the recipe that created this particular planet, and they help us understand how planets like this one are made.”

“Further analysis of the components remaining in the planet's atmosphere may help us understand why planets like GJ 3470b became so appetizing.”

This month, the authors 244th Meeting of the American Astronomical Society In Madison, Wisconsin.

Source: www.sci.news

Astronomers find parallel jets and disks around nearby multiple star system

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Astronomers Atacama Large Millimeter/Submillimeter Array (ALMA) Mid-infrared measuring instrument (mm) NASA/ESA/CSA James Webb Space Telescope A twin disk and parallel jets were discovered in the young star system WL20.

Barsoni othersTwin disks and jets erupting from a pair of young stars in WL20. Image credit: NSF / NRAO / B. Saxton / NASA / JPL-Caltech / Harvard-Smithsonian CfA.

WL20 It is located in the Rho Ophiuchus Molecular Cloud Complex, more than 400 light years from Earth.

“What we found was absolutely surprising,” said Dr Mary Barthony, lead author of the study.

“We've known about the WL20 system for some time, but what caught our attention was that one of the stars in the system appeared to be much younger than the others.”

“Using MIRI and ALMA together, we were able to see that this one star is actually two stars next to each other.”

“Each of these stars was surrounded by a disk, and each disk emitted a jet parallel to the others.”

ALMA and Webb's MIRI observe very different parts of the electromagnetic spectrum.

Used together, they allowed astronomers to discover these hidden twins in the stellar system's radio and infrared wavelengths: ALMA found the disk, and MIRI found the jet.

They analyzed archived ALMA data to reveal the composition of the disk, and MIRI data to reveal the chemical composition of the jet.

They also analyzed high-resolution images, revealing the size of the massive disk – about 100 times the distance between Earth and the Sun.

“Without MIRI we would never have known these jets even existed, which is amazing,” Dr Barthony said.

“ALMA's high-resolution observations of the disks surrounding the two newly observed stars reveal the structure of the disks.”

“Someone looking at this ALMA data and not knowing there are twin jets would think it's a big edge-on disk with a hole in the middle, rather than two edge-on disks and two jets. That's pretty remarkable.”

Combining multi-wavelength data from ALMA and Webb revealed the complex processes involved in the formation of several stellar systems.

“We plan to take advantage of ALMA's future upgrades, such as the broadband sensitivity upgrade, to continue unlocking the mysteries surrounding the birth of stars and planetary systems,” the researchers said.

They are, result in 244th Meeting of the American Astronomical Society In Madison, Wisconsin.

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Mary Barthony others2024. Twin jets and twin discs: JWST MIRI and ALMA discoveries in the young WL20 multiple star system. 224 AustraliaAbstract #253

Source: www.sci.news

Amateur astronomers find speedy L-type subdwarf star in our cosmic neighborhood

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At an estimated distance of 140 parsecs (457 light years), the L-type subdwarf star CWISE J124909+362116.0 (J1249+36 for short) has a total velocity of at least 600 km/s, exceeding the local galactic escape velocity. Remarkably, the star may have been ejected from a globular cluster in the outer reaches of the Milky Way sometime in the past 10 to 30 million years.

A simulation of the hypothetical J1249+36 white dwarf binary ends with the white dwarf star exploding in a supernova. Image courtesy of Adam Makarenko / WM Keck Observatory.

J1249+36 was first discovered by a citizen scientist. Backyard Worlds: Planet 9 Program.

The star immediately stood out as its speed across the sky was initially estimated to be around 600 km/s.

This speed is fast enough for the star to escape the gravity of the Milky Way, making it a potential hypervelocity star.

To better understand the properties of J1249+36, Professor Adam Burgasser of the University of California, San Diego, and his colleagues used the W. M. Keck Observatory to measure its infrared spectrum.

These data revealed that the object is a rare L-type subdwarf star, a class of stars with an extremely low mass and temperature.

Spectral data and imaging data from multiple ground-based telescopes allowed the team to precisely measure J1249+36's position and velocity in space, and predict its orbit within the Milky Way galaxy.

“What makes this source so interesting is that its speed and orbit suggest it is moving fast enough to escape the Milky Way,” Professor Burgasser said.

The researchers focused on two scenarios to explain J1249+36's unusual orbit.

In the first scenario, J1249+36 was originally a low-mass companion to a white dwarf.

If a companion star is in a very close orbit with a white dwarf, it can transfer mass, causing periodic explosions called novae. If the white dwarf gathers too much mass, it can collapse and explode as a supernova.

“In this type of supernova, the white dwarf is completely destroyed, so the companion star is freed to fly away at the orbital velocity it was originally moving at, plus a bit of a supernova blast,” Prof Burgasser said.

“Our calculations show that this scenario holds true. However, because the white dwarf no longer exists and the remnants of the explosion that probably occurred millions of years ago have already dissipated, we have no conclusive evidence that this is its origin.”

In the second scenario, J1249+36 was originally a member of a globular cluster, a tightly bound group of stars that is immediately recognizable by its distinctive spherical shape.

The centers of these clusters are predicted to contain black holes with a wide range of masses.

These black holes can also form binary systems, and such systems prove to be great catapults for any star that happens to get too close to them.

“When a star encounters a black hole binary, the complex dynamics of this three-body interaction can cause the star to be thrown out of the globular cluster,” said Dr Kyle Kremer, an astronomer at the University of California, San Diego.

The scientists ran a series of simulations and found that, on rare occasions, these types of interactions can cause low-mass subdwarf stars to be ejected from globular clusters and follow orbits similar to the one observed in J1249+36.

“This is a proof of concept, but we don't actually know which globular cluster this star is from,” Dr Kremer said.

“By tracking J1249+36 back in time, we find that it lies in a very crowded part of the sky that may be hiding undiscovered star clusters.”

To determine whether one of these scenarios, or some other mechanism, can explain J1249+36's orbit, the team wants to take a closer look at its elemental composition.

For example, the explosion of a white dwarf star could produce heavy elements that could pollute J1249+36's atmosphere as they escape.

Stars in the Milky Way's globular clusters and satellite galaxies also have unique presence patterns that could shed light on the origins of J1249+36.

“We're basically looking for a chemical fingerprint that will pinpoint exactly what system this star came from,” says Roman Gerasimov, also of the University of California, San Diego.

“Whether J1249+36's high-speed movement is the result of a supernova, a chance encounter with a black hole binary, or some other scenario, its discovery offers astronomers a new opportunity to learn more about the history and dynamics of the Milky Way.”

The astronomers discovery this week's 244th Meeting of the American Astronomical Society In Madison, Wisconsin.

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Adam Burgasser others2024. A superfast L-type subdwarf star passes near the solar system. 224 AustraliaAbstract #3

Source: www.sci.news

Astronomers report that the moons orbiting asteroid Dinkinesh are in a contact binary configuration

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Dinkinesh is a small asteroid orbiting the Sun near the inner edge of the main asteroid belt. NASA’s Lucy spacecraft recently revealed that this asteroid, with an effective diameter of just 720 meters, is unexpectedly complex. The asteroid has a pronounced valley covered by an equatorial ridge and is currently orbited by a contact binary moon, named Seram, which consists of two nearly equal lobes with diameters of 210 meters and 230 meters. The moon orbits at a distance of 3.1 kilometers from Dinkinesh, has an orbital period of about 52.7 hours, and is tidally locked.

Stereo image pair (a-c) taken by the L’LORRI instrument aboard NASA’s Lucy spacecraft on November 1, 2023, shows asteroid Dinkinesh. Yellow and rose dots indicate valley and ridge features, respectively. These images have been sharpened and processed to enhance contrast. Image (d) shows a side-on view of Dinkinesh and its moon Ceram, taken a few minutes after closest approach. Image credit: NASA/GSFC/SwRI/Johns Hopkins APL/NOIRLab.

“We want to understand the strength of small bodies in the solar system because it’s important to understanding how planets like Earth got here,” said Dr. Hal Levison, a research scientist at Southwest Research Institute and Lucy principal investigator.

“Essentially, planets formed when a bunch of tiny objects orbiting the sun, like asteroids, collided with each other.”

“How objects behave when they collide – whether they break or stick together – has a lot to do with the object’s strength and internal structure.”

The researchers believe that how Dinkinesh responded to stress may reveal something about its inner workings.

As it rotated in sunlight for millions of years, tiny forces from thermal radiation radiating from the asteroid’s warm surface created tiny torques that caused Dinkinesh to spin gradually faster, and the accumulated centrifugal forces caused parts of the asteroid to become more elongated.

This event likely sent debris into close orbit, providing the raw material for the formation of the ridge and moons.

If Dinkinesh had been a weaker, more mobile mass of sand, its particles would have gradually migrated toward the equator and then blasted off into orbit as it rotated faster.

But the images suggest that, like rock, the Dinkinesh asteroid was stronger than a fluid and held together longer, until it eventually disintegrated under pressure and broke into larger pieces. Still, the force needed to break up a small asteroid like Dinkinesh is tiny compared to most rocks on Earth.

“This valley suggests a sudden collapse, more like an earthquake, where stress builds up gradually and then is suddenly released, rather than the slow process that creates sand dunes,” said Dr. Keith Noll, a research scientist at NASA’s Goddard Space Flight Center and a Lucy scientist.

“These features show that Dinkinesh has some strength, and we can do a bit of historical reconstruction to see how this asteroid evolved,” Dr Levison said.

“During that collapse, the rocks broke apart and things separated, forming a disk of material, some of which rained down to the surface and formed the ridge.”

“We think that some of the material in the disk formed the moon Ceram, which is actually a structure where two celestial bodies are in contact with each other, known as a contact binary. The details of how this unusual moon formed remain a mystery.”

of Investigation result Published in the journal Nature.

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H.F. Levison others2024. Contact binary moon of asteroid (152830) Dinkinesh. Nature 629, 1015-1020; doi: 10.1038/s41586-024-07378-0

Source: www.sci.news

Astronomers find record-breaking slowest rotating neutron star emitting radio waves

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Neutron stars typically spin quickly, taking just a few seconds or even a fraction of a second to complete one revolution around their axis, but one neutron star labeled ASKAP J1935+2148 bucks this rule, emitting radio signals at a relatively slow interval of 53.8 minutes.

Artist's impression of a neutron star. Image courtesy of Sci.News.

“We're used to extreme examples when studying radio-emitting neutron stars, so the discovery of such a compact star that is still emitting radio waves despite rotating slowly was unexpected,” said Professor Ben Stappers, from the University of Manchester.

“This new generation of radio telescopes demonstrates that pushing the boundaries of our search space will reveal surprises that will shake up our understanding.”

At the end of their lives, massive stars use up all their fuel and undergo a spectacular explosion called a supernova.

What remains is a stellar remnant called a neutron star, which consists of trillions of neutrons packed into an extremely dense sphere with a mass 1.4 times that of the Sun, packed into a radius of just 10 km.

Astronomers detected an unexpected radio signal from ASKAP J1935+2148 that traveled about 16,000 light-years to Earth.

The nature of its radio emission and the rate of change of its rotation period suggest that it is a neutron star, but further study is needed to confirm what this object is.

“This discovery relied on the complementary capabilities of the ASKAP and MeerKAT telescopes, combined with our ability to probe these objects on timescales of minutes, and examine how their radiation changes from second to second,” said Dr Kaustubh Rajwade, an astronomer at the University of Oxford.

“Such synergies can shed new light on how these compact objects evolve.”

ASKAP J1935+2148 was detected by CSIRO's ASKAP radio telescope in the Wadjari Yamatji region of Western Australia.

“What's interesting is that this object exhibits three different radiation states, each with completely different properties to the others,” said Dr Manisha Caleb, an astronomer at the University of Sydney.

“The MeerKAT radio telescope in South Africa played a key role in distinguishing between these states.”

“If the signals had not come from the same point in the sky, it would be hard to believe that it was the same object producing these different signals.”

“Until the arrival of these new telescopes, the dynamic radio sky was relatively unexplored,” said Professor Tara Murphy, from the University of Sydney.

“Now we can look deeply and frequently see a variety of unusual phenomena.”

“These events give us insight into how physics works in extreme environments.”

This discovery paper In the journal Natural Astronomy.

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M. Caleb othersA radio transient phenomenon in which the radiation state switches with a period of 54 minutes. Nat AstronPublished online June 5, 2024; doi: 10.1038/s41550-024-02277-w

Source: www.sci.news

Astronomers document extraterrestrial exoplanets

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The new catalogue, created as part of the TESS-Keck survey, includes 126 strange planets outside our solar system, ranging from unusual worlds with extreme environments to those that could potentially support life as we know it.

Artist's impression of the 126 planets in the new TESS-Keck survey catalog is based on data such as planet radius, mass, density, and temperature. Question marks represent planets that need more data for full characterization. Image courtesy of W. M. Keck Observatory/Adam Makarenko.

“Relatively few known exoplanets have had both their mass and radius measured,” said Steven Kane, professor at the University of California, Riverside, and principal investigator of the TESS-Keck survey. paper Published in Astrophysical Journal Supplement.

“Combined, these measurements tell us what the planet is made of and how it formed.”

“With this information, we will be able to answer the question of where our solar system fits in the grand scheme of other planetary systems.”

Professor Kane and his colleagues analysed more than 13,000 radial velocity (RV) measurements to calculate the masses of 120 confirmed planets and six candidate planets spread across the northern sky.

“These RV measurements allow astronomers to detect and characterize these exoplanetary systems,” said astrophysicist Ian Crossfield of the University of Kansas.

“When we see a star wobbling back and forth in a regular pattern, we can infer the presence of orbiting planets and measure their masses.”

Several planets discovered in the TESS-Keck survey stand out as touchstones for improving astronomers' understanding of the diverse ways planets form and evolve.

in Related Papers In Astronomical JournalAstronomers have announced the discovery of two new planets orbiting a sun-like star.

The first is a sub-Saturnian planet with a mass and radius intermediate between Neptune and Saturn.

“There's been some debate about whether sub-Saturn planets are truly rare or whether we're just bad at finding them,” said Michelle Hill, a graduate student at the University of California, Riverside.

“So planet TOI-1386b is an important addition to this planetary group.”

TOI-1386b takes just 26 days to orbit its star, while its neighbour, a planet with a mass similar to that of Saturn, takes 227 days to orbit the same star.

in Related ArticlesThe researchers described TOI-1437b, a planet about half the size of Neptune that orbits a sun-like star every 19 days.

“Planets smaller than Neptune and larger than Earth are the most common worlds in our galaxy, but they don't exist in our solar system,” said Daria Pidhorodetka, a graduate student at the University of California, Riverside.

“With each new discovery, we are reminded of how diverse the universe is, and that our place in it may be more unique than we can understand.”

The catalog also contains detailed descriptions of planets that, unlike the Sun, orbit extremely short distances around their stars.

One is so close to the orange dwarf that it completes an orbit in less than 12 hours.

“TOI-1798c orbits its star so quickly that a year on the planet lasts less than half an Earth day,” said Alex Polansky, a graduate student at the University of Kansas.

“Because these planets are so close to their stars, they are extremely hot and receive more than 3,000 times the radiation that Earth receives from the Sun.”

“Being in this extreme environment means that the planet is likely losing any atmosphere it may have originally formed.”

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Alex S. Polanski other2024. TESS-Keck Survey. XX. Uniform RV analysis of 15 new TESS planets and all survey targets. AppJS 272, 32; Source: 10.3847/1538-4365/ad4484

Michelle L. Hill other2024. TESS-Keck Survey. XIX. Warm transiting sub-Saturn-mass and non-transiting Saturn-mass planets orbiting solar analogues. AJ 167, 151; Source: 10.3847/1538-3881/ad2765

Daria Pidhorodetka other. 2024. TESS-Keck Survey. XXII. TOI-1437 in Near-Neptune Orbit. arXiv: 2405.12448

Source: www.sci.news

Astronomers Find Milky Way Center is Ventilated

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Astronomers using NASA's Chandra X-ray Observatory have discovered an “exhaust vent” that directs hot gas away from Sagittarius A*, the supermassive black hole at the center of the Milky Way galaxy. The vent is about 26,000 light-years from Earth and is connected to a previously discovered chimney-like structure perpendicular to the galactic plane. Chandra's data shows a cylindrical tunnel that helps collect gas towards the outer edge of the Milky Way. The results reveal how the Milky Way's black hole takes in and rejects matter.

This image shows a region near the center of the Milky Way galaxy in X-rays and radio waves. At the bottom of the image, near the center, there are knots of shiny, tangled material that resemble paint splatters. This is the brightest region in the image and contains the supermassive black hole at the center of the galaxy known as Sagittarius A*. The bottom third of the image looks like an angry firestorm. Red and orange stripes were scattered in all directions, as if the embers of a fire had crackled and shot into the air all at once. A flame-like structure is licking from the right side towards the center. Most of the image is injected with a wispy blue cloud indicating his X-rays detected by Chandra. In some places, wispy blue clouds appear to form balls of blue-green light, known as dust rings. They are caused by X-rays from a bright X-ray source reflecting off the dust around them. These dust rings resemble underwater lights glowing in a cloudy pool at night. Rising from Sagittarius A* in the center of the image is a pillar of blue light called a chimney. This chimney of hot gas is surrounded by a red cloud filled with stars, appearing as a small red speck. Near the top of the blue pillar is a light blue stripe surrounded by an illustrated gray box. This line is called the chimney exhaust. Immediately to the left is another illustrated box showing a close-up image of the chimney vent that Chandra observed.Image credits: NASA / CXC / Chicago Space / Mackey other. / NRF / SARAO / MeerKAT / SAO / N. Walk.

The chimney begins at the center of the Milky Way and stands perpendicular to the galaxy's spiral disk.

Astronomers previously identified the chimney using X-ray data from NASA's Chandra mission and ESA's XMM Newton mission.

The radio emissions detected by the MeerKAT radio telescope show the influence of the magnetic field surrounding the gas in the chimney.

The latest Chandra data reveals several X-ray ridges nearly perpendicular to the galactic plane.

Astronomers believe these are cylinder-shaped tunnel walls that help collect hot gas as it moves upwards along the chimney and away from the center of the galaxy. .

The newly discovered vent is located near the top of a chimney about 700 light-years from the center of the galaxy.

“We suspected that the magnetic field was acting as a chimney wall, allowing hot gases to rise through it like smoke,” said Dr. Scott McKee, an astronomer at the University of Chicago.

“I just discovered an exhaust near the top of the chimney.”

Astronomers believe the vent formed when hot gas rising through the chimney collided with cooler gas in its path.

The brightness of the exhaust wall in X-rays is caused by the shock wave created by this collision, similar to the sonic boom from a supersonic airplane.

The left side of the exhaust port is thought to be particularly bright because the upwardly flowing gas hits the tunnel wall at a more direct angle and with more force than other areas.

The researchers believe that the hot gas originates from a series of events in which material falls into Sagittarius A*, then erupts from the black hole, sending gas upward along the chimney and out the exhaust vent. I think it is most likely that it did.

However, it is not known exactly how often black holes are fed.

Previous studies have shown that dramatic X-ray flares occur every few hundred years at or near the central black hole, so that these flares send hot gases upward through the exhaust vent. may play an important role in pushing up.

Astronomers also estimate that Sagittarius A* tears apart and swallows a star approximately every 20,000 years.

Such an event would lead to a powerful and explosive release of energy, much of which would rise through the chimney vent.

Dr Mark Morris, an astronomer at the institute, said: 'We don&#39t know whether this energy and heat is caused by a large amount of material being thrown into Sagittarius A* at once. It&#39s like being thrown into it.” University of California, Los Angeles.

“Alternatively, it could result from multiple small loads being fed into the black hole, similar to kindlings thrown in periodically.”

Particles and energy within the vents provide clues about the origins of two mysterious and much larger structures near the center of the Milky Way. Fermi bubbles observed in gamma-rays by NASA&#39s Fermi Gamma-ray Space Telescope, and eROSITA bubbles detected by NASA&#39s Fermi Gamma-ray Space Telescope. ESA&#39s eROSITA X-ray telescope.

These are both pairs of structures that extend thousands of light-years away from the center of our galaxy.

These provide important information about past explosive activity near the center of the galaxy.

Both the Fermi and eROSITA bubbles are aligned along the direction of the chimney and a second X-ray chimney that starts at the center of the galaxy and points in the opposite direction.

The funnel effect of the exhaust near the top of the chimney keeps the hot gases concentrated as they move upwards, which can promote the formation of a bubble agglomerate structure.

“The origin of the Fermi and eROSITA bubbles is one of the greatest mysteries facing the study of high-energy radiation from the Milky Way,” said Dr. Gabriele Ponti, an astronomer at Italy&#39s National Institute of Astrophysics.

“We discovered small structures that may play a major role in the creation of these giant bubbles.”

a paper Regarding the survey results, astrophysical journal.

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Scott C. McKee other. 2024. X-rays from the central “exhaust” of the chimney at the center of the galaxy. APJL 966, L32; doi: 10.3847/2041-8213/ad3248

Source: www.sci.news

Discovery of ancient star in Milky Way halo estimated to be 12-13 billion years old by astronomers

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Astronomers at the Massachusetts Institute of Technology have discovered very old stars in the Milky Way’s halo, a cloud of stars that covers the entire disk of our galaxy. These objects formed between 12 and 13 billion years ago, when the first galaxies were beginning to form. Researchers believe that each star once belonged to its own dwarf galaxy, which was later absorbed into the larger but ever-growing Milky Way, making them known as small accreting star systems (SASS). It’s called a star.

Artist’s concept of the Milky Way galaxy. Image credit: Pablo Carlos Budassi / CC BY-SA 4.0.

“Given what we know about galaxy formation, these oldest stars should definitely exist,” says MIT professor Anna Froebel.

“They are part of our cosmic family tree. And now we have a new way to find them.”

As they discover similar SASS stars, Professor Froebel and his colleagues hope to use them as analogues of ultrafaint dwarf galaxies, which are thought to be some of the first living galaxies in the universe.

These galaxies remain intact today, but they are too distant and faint for astronomers to study in detail.

SASS stars may once have belonged to similar primitive dwarf galaxies, but they are now located within the Milky Way and are much closer, making them more accessible for understanding the evolution of ultrafaint dwarf galaxies. This could be the key.

“Now we can look for more brighter analogs in the Milky Way and study their chemical evolution without chasing these very faint stars,” Professor Froebel said.

The low chemical abundances of these stars suggest that they first formed between 12 and 13 billion years ago.

In fact, their low chemical signature was similar to what astronomers had previously measured for several ancient, ultra-dark dwarf galaxies.

Are the team’s star players from similar galaxies? And how did they come to exist in the Milky Way?

Based on a hunch, scientists studied the orbital patterns of stars and how they move across the sky.

The three stars are located in different locations throughout the Milky Way’s halo and are estimated to be about 30,000 light-years from Earth.

When astronomers used observations from ESA’s Gaia satellite to trace the movement of each star around the galaxy’s center, they noticed something strange. All three stars appeared to be in motion, compared to most of the stars in the main disk, which move like cars on a race track. Wrong way.

In astronomy, this is known as retrograde motion, and is information that the object was once accreted or pulled in from elsewhere.

“The only way to get a star wrong from other members is if you throw it the wrong way,” Professor Froebel says.

The fact that these three stars orbit in a completely different way than the rest of the galactic disk or halo, combined with the fact that their chemical abundances are low, suggests that these stars are actually It was strongly argued that it was ancient and once belonged to an earlier era, a small dwarf galaxy that fell into the Milky Way at a random angle and continued its stubborn orbit billions of years later.

The authors were interested in whether retrograde motion was a feature of other ancient stars in the halo that astronomers had previously analyzed, and they looked at the scientific literature and found similarly low strontium and barium contents, discovered 65 other stars that appear to be moving in retrograde motion as well. Galaxy flow.

“Interestingly, they are all traveling very fast, hundreds of kilometers per second, in opposite directions,” Professor Froebel said.

“They’re on the run! We don’t know why it happened, but this is the piece of the puzzle we need and we never expected it when we started.”

Researchers are keen to find other ancient SASS stars, and now have a relatively simple recipe for doing so. First, they look for stars with low chemical abundance, then track their orbital patterns for signs of retrograde motion.

Researchers hope this method will uncover a small but significant number of the universe’s oldest stars, out of the more than 400 billion stars in the Milky Way.

“I really enjoyed working with three female undergraduates. It was a first for me,” said Professor Froebel.

“This is just an example of the MIT way. It is. And anyone who says, ‘I want to participate,’ can do so, and good things happen.”

team’s paper Published in Royal Astronomical Society Monthly Notices.

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Hilary Diane Anders other. 2024. The oldest star with a small amount of neutron-capturing elements and originating from an ancient dwarf galaxy. MNRAS 530 (4): 4712-4729; doi: 10.1093/mnras/stae670

Source: www.sci.news

Astronomers observe massive flare emitted by Messier 82 magnetar

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Using sensitive instruments aboard ESA’s International Gamma-ray Astrophysics Laboratory (Integral) mission, astronomers GRB231115A Taken from the center of Messier 82 (M82, NGC 3034, or the Cigar Galaxy). Messier 82 (M82, NGC 3034, or Cigar Galaxy) is a starburst irregular galaxy located 12 million light-years away in the constellation Ursa Major. They say the spectral and timing characteristics of GRB 231115A, as well as the lack of X-ray and optical observations and gravitational wave signals several hours after the event, indicate that this outburst was the result of a giant flare from a magnetar. Suggests. They conclude that starburst galaxies like Messier 82, which are known to produce magnetars, could be promising targets for studying giant flares.

On November 15, 2023, Integral detected a burst of gamma rays that lasted just one-tenth of a second. The detection was sent to the Integral Science Data Center, where software determined it came from the nearby galaxy Messier 82. A small square on Integral's map indicates the location of the burst. Blue circles on the two cropped images indicate corresponding locations. Image credit: ESA / Integral / XMM-Newton / INAF / TNG / M. Rigoselli, INAF.

Giant flares are short explosive events that release very large amounts of energy as gamma-ray bursts (GRBs).

Only three such flares have been observed from magnetars in our Milky Way galaxy and the nearby Large Magellanic Cloud in the past roughly 50 years.

Observations of giant flares from distant magnetars are hampered by the fact that at long distances it is difficult to identify the source of the energy burst.

“Some young neutron stars have very strong magnetic fields, more than 10,000 times stronger than a typical neutron star. These are called magnetars. They emit energy as flares, and sometimes these flares can be huge,” said ESA astronomer Dr. Ashley Climes.

“However, in the past 50 years of gamma-ray observations, huge flares from our galaxy's magnetars have only been observed three times.”

“These explosions are extremely powerful. The explosion detected in December 2004 came from 30,000 light-years away from us, but was still powerful enough to affect the upper layers of Earth's atmosphere. It's like a solar flare coming from much closer to us.

“The flare detected by Integral is the first confirmation of the existence of a magnetar outside the Milky Way,” said Dr. Sandro Meleghetti, an astronomer at the National Institute of Astrophysics.

“We suspect that some of the other 'short gamma-ray bursts' revealed by Integral and other satellites are also giant flares from magnetars.”

“This discovery will begin the search for other extragalactic magnetars. If we can find more stars, we will be able to understand how often these flares occur and how the stars lose energy in the process. We can begin to understand that,” Dr. Cromes said.

“However, such short-lived explosions can only be caught by chance if the observatory is already pointing in the right direction,” said Dr. Jan-Uwe Ness, a scientist at the Integral project.

“This makes Integral, with its wide field of view more than 3,000 times the area of ​​the sky covered by the Moon, extremely important for these detections.”

“Messier 82 is a bright galaxy in which star formation occurs,” the authors said.

“In these regions, massive stars are born, live short, turbulent lives, and leave behind neutron stars.”

“The discovery of magnetars in this region confirms that magnetars are likely young neutron stars.”

“The search for additional magnetars will continue in other star-forming regions to understand these extraordinary objects.”

of findings It was published in the magazine Nature.

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S. Meleghetti other. A giant magnetar flare in the nearby starburst galaxy M82. Nature, published online March 7, 2024. doi: 10.1038/s41586-024-07285-4

Source: www.sci.news

Astronomers discover large ejection of dipolar material from NGC 4383

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A large number of stars are born in the center NGC4383where a unique galaxy is located 74 million light years It is located beyond the constellation Coma. The largest lose mass through powerful winds over their lifetime, eventually exploding into violent supernovae. These stellar winds and supernovae drag away some of NGC 4383's gas reservoir. The bright red filaments indicate hydrogen gas ejected at least 20,000 light-years from the galaxy. This process controls the rate at which stars form within the galaxy, as this gas is carried away from the galactic center rather than remaining to form the next generation of stars.

watt other. We mapped the chemical composition and motion of NGC 4383's outflow in detail, providing insight into the mechanisms that caused the dramatic outflow seen in this image from ESO's Very Large Telescope.Image credit: ESO / Watts other.

Gas outflow is important for controlling the rate and duration at which galaxies continue to form stars.

The gas ejected by these explosions can pollute the space between stars within galaxies and even between galaxies, becoming permanently suspended in the intergalactic medium.

Dr Adam Watts, an astronomer at the University of Western Australia's node at the International Radio Center, said: “This outflow is the result of a powerful stellar explosion at the center of the galaxy, potentially spewing out huge amounts of hydrogen and heavy elements. There is a gender,” he said. Astronomical Research (ICAR).

“The mass of gas released is equivalent to more than 50 million suns.”

“Spills are very difficult to detect, so very little is known about the physics of spills and their properties.”

“The ejected gas is extremely rich in heavy elements, providing a unique insight into the complex process by which metals mix with hydrogen in the ejected gas.”

“In this particular case, oxygen, nitrogen, sulfur and many other chemical elements were detected.”

astronomers are muse (Multi-unit Spectroscopic Explorer) Turn on the instrument ESO's super large telescope (VLT) Created a high-resolution map of NGC 4383 in northern Chile.

Data were collected as part of VLT/MUSE's larger program MAUVE (MUSE and ALMA Unveiling the Virgo Environment).

“We designed MAUVE to investigate how physical processes, such as gas outflow, help stop star formation in galaxies,” said West, also at the International Center for Radio Astronomy Research (ICRAR). said Professor Barbara Catinella of the Australian University of Nord.

“NGC 4383 was our first target because we thought something very interesting might be happening, and the data exceeded all expectations.”

“In the future, we hope that MAUVE's observations will reveal in great detail the importance of gas outflow in the local universe.”

team's paper Published in Royal Astronomical Society Monthly Notices.

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Adam B. Watts other. 2024. Mauve: A 6 kpc bipolar outflow launched from NGC 4383, one of the most Hi-rich galaxies in the Virgo cluster. MNRAS 530 (2): 1968-1983; doi: 10.1093/mnras/stae898

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454 new asteroids discovered in the main asteroid belt by astronomers

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632 main-belt asteroids (178 known objects and 454 unknown objects) have been identified in archival images from the NASA/ESA Hubble Space Telescope. Citizen scientists from around the world contributed to the discovery of this asteroid. Professional astronomers identified the asteroid using a combination of volunteer efforts and machine learning algorithms.

This Hubble image of barred spiral galaxy UGC 12158 looks like someone took it with a white marking pen. In reality, this is a combination of long exposures of a foreground asteroid moving within Hubble's field of view, adding light bombardment to observations of the galaxy. The galaxy was photographed several times. The dashed pattern is proof of this. Due to parallax, the asteroid appears as a curved trajectory. Hubble is not stationary, but orbits around the Earth, giving the illusion of a faint asteroid swimming along a curved trajectory. This unknown asteroid is located inside the solar system's asteroid belt, so it is 10 trillion times closer to Hubble than the background galaxy. Image credits: NASA / ESA / Hubble / Pablo García Martín, UAM / Joseph DePasquale, STScI / Alex Filippenko, University of California, Berkeley.

More than 4 billion years ago, the eight major planets around the sun formed by sweeping up debris from the vast disk of dust and gas surrounding the sun.

This is common in the birth process of planets, and the NASA/ESA Hubble Space Telescope has for the first time optically observed a similar disk surrounding a newborn star, providing a glimpse into the solar system's formative years.

Four billion years later, debris still litters the planet's construction yards.

Most of this ancient space debris, or asteroids, lies between the orbits of Mars and Jupiter within the main asteroid belt.

“We are starting to learn more about the presence of a small number of main-belt asteroids,” said Dr. Pablo García Martín, an astronomer at the Autonomous University of Madrid.

“We were surprised to see so many candidate objects.”

“We've had some hints that this population exists, but we're now confirming it with a random asteroid population sample obtained using the entire Hubble archive.”

“This is important for gaining insight into models of the evolution of the solar system.”

Since Hubble orbits around the Earth at high speed, Hubble exposure allows us to follow its trail and capture a wandering asteroid.

When viewed from a telescope on Earth, the asteroid leaves streaks across the photo.

The asteroid appears as an unmistakable curved trajectory in the photo, making the Hubble exposure a “photobomb.”

Hubble observes the asteroid from different perspectives as it moves around Earth, but the asteroid also moves along its own orbit.

By knowing Hubble's position during observations and measuring the curvature of its stripes, scientists can determine the distance to the asteroid and estimate the shape of its orbit.

Most of the asteroids involved are in the main belt between the orbits of Mars and Jupiter.

Their brightness is measured by Hubble's sensitive camera. Then, by comparing its brightness and distance, we can estimate its size.

The faintest asteroid found in the survey is approximately 40 million times less bright than the faintest star visible to the human eye.

“Because the asteroid's position changes over time, you can't find the asteroid's location just by entering the coordinates, because the asteroid may not be there at a different time,” Melin said.

“As astronomers, we don't have time to study images of every asteroid.”

“So we came up with the idea of ​​collaborating with more than 10,000 citizen science volunteers to browse the massive Hubble archive.”

of result appear in the diary astronomy and astrophysics.

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Pablo Garcia-Martin other. 2024. Hubble Asteroid Hunter III. Physical properties of newly discovered asteroids. A&A 683, A122; doi: 10.1051/0004-6361/202346771

Source: www.sci.news