Tag Archives: stars

Hubble’s Stunning Photomosaic of the Andromeda Galaxy Unveils Countless Stars

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A century ago, American astronomer Edwin Hubble was the first to prove that this so-called “spiral nebula” lies about 2.5 million light-years away from the Milky Way. To date, the NASA/ESA Hubble Space Telescope has achieved the most comprehensive survey of the Andromeda Galaxy. It took more than 10 years to collect the data. This colorful portrait which captures the glow of 200 million stars and was created from over 600 snapshots.

This is the largest photomosaic ever assembled from Hubble observations. A panoramic view of the neighboring Andromeda galaxy, 2.5 million light years away. Image credit: NASA/ESA/B. Williams, University of Washington.

The Andromeda Galaxy (Mesier 31) is located 2.5 million light-years away and is the closest large galaxy neighbor to the Milky Way.

Hubble's sharp imaging power can resolve more than 200 million stars in the galaxy and detect only those stars brighter than the Sun. They look like grains of sand on a beach. But that's just the tip of the iceberg.

Andromeda's total population is estimated to be 1 trillion stars, with many less massive stars falling below Hubble's sensitivity limit.

“Imaging the Andromeda Galaxy was a difficult task because it is a much larger target than the galaxies that Hubble regularly observes, often billions of light years away,” Washington said. said university astronomer Zhuo Chen and colleagues.

“The complete mosaic was performed under two Hubble observing programs. In total, it required more than 1,000 Hubble orbits spanning more than 10 years.”

“This panorama… Panchromatic Hubble Andromeda Treasury (PHAT) Program About ten years ago. ”

The Andromeda Galaxy is tilted 77 degrees to Earth's perspective and is seen almost head-on. Areas of interest include (a) a photobombing of bright blue clusters of stars embedded within the galaxy, background galaxies visible in the distance, and some bright foreground stars that are actually within the Milky Way; Masu. (b) NGC 206 is Andromeda's most prominent nebula. (c) A young population of newborn blue stars. (d) Satellite galaxy M32. This could be the remnant nucleus of a galaxy that once collided with Andromeda. (e) A dark dust band across countless stars. Image credit: NASA/ESA/B. Williams, University of Washington.

“Images were acquired at near-ultraviolet, visible, and near-infrared wavelengths. Hubble's advanced survey camera (ACS) and wide field camera 3 (WFC3) To photograph the northern half of Andromeda. ”

“The follow-up of this program is Panchromatic Hubble Andromeda Tropical Treasury (PHAST), added images of about 100 million stars in the southern half of Andromeda. ”

“This region is structurally unique and more sensitive to the history of galactic mergers than the northern disk mapped by the PHAT survey.”

“The combined program collectively covers Andromeda's entire disc, which is tilted 77 degrees to Earth's field of view and viewed almost head-on.”

“The galaxy is so large that the mosaic is assembled from about 600 separate fields of view.”

of result described in the paper. astrophysical journal.

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Zhuo Chen others. 2025. Fast. Panchromatic Hubble Andromeda Southern Treasury. I. Ultraviolet and optical photometry of over 90 million stars in M31. APJ 979, 35;doi: 10.3847/1538-4357/ad7e2b

Source: www.sci.news

LIGO hunts for gravitational waves produced by mountains on neutron stars

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While the solar system’s moons such as Europa and Enceladus have thin crusts over deep oceans, Mercury has a thin crust over a large metallic core. Thin sheets are generally likely to wrinkle. Europa has linear features, Enceladus has “tiger stripes” and Mercury has foliated cliffs. Neutron stars may have similar characteristics. These neutron star mountains can generate detectable oscillations in space and time known as gravitational waves, according to a new study.

Artist’s impression of a neutron star. Image credit: Sci.News.

Neutron stars are a trillion times denser than lead, and their surface features are largely unknown.

Nuclear theorists investigated the mountain-building mechanisms active on the moons and planets of the solar system.

Some of these mechanisms suggest that neutron stars likely have mountains.

A mountain in a neutron star would be much more massive than any mountain on Earth. They are so huge that the gravitational pull from these mountains alone can generate gravitational waves.

of Laser interferometer Gravitational wave observatory (LIGO) is currently looking for these signals.

“These waves are so weak that they require highly detailed and sensitive techniques carefully tuned to the expected frequencies and other signal characteristics,” said nuclear astrophysicist Jorge Morales and professor Charles Horowitz at Indiana University. It can only be discovered through search.”

“The first detection of continuous gravitational waves opens a new window on the universe and will provide unique information about neutron stars, the densest objects after black holes.”

“These signals may also provide sensitive tests of fundamental laws of nature.”

The authors investigated the similarities between neutron star mountains and surface features of solar system objects.

“While both neutron stars and certain moons, such as Jupiter’s moon Europa and Saturn’s moon Enceladus, have a thin crust over a deep ocean, Mercury has a thin crust over a large metallic core. The thin sheet Wrinkles are universally possible,” they said.

“Europa has linear features, Enceladus has tiger-like stripes, and Mercury has curved, step-like structures.”

“Mountained neutron stars may have similar types of surface features that can be discovered by observing continuous gravitational wave signals.”

“Earth’s innermost core is anisotropic, and its shear modulus is direction-dependent.”

“If the material in the neutron star’s crust is also anisotropic, a mountain-like deformation will occur, and its height will increase as the star rotates faster.”

“Such surface features could explain the maximum spin observed in neutron stars and the minimum possible deformation of radio-emitting neutron stars known as millisecond pulsars.”

team’s paper Published in a magazine Physical Review D.

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JA Morales and CJ Horowitz. 2024. The anisotropic neutron star crust, the mountains of the solar system, and gravitational waves. Physics. Rev.D 110, 044016; doi: 10.1103/PhysRevD.110.044016

Source: www.sci.news

Astronomers reveal that new high-speed radio bursts originated from neutron stars’ magnetospheres

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A new study has provided the first definitive evidence that fast radio bursts can originate from the magnetosphere, the highly magnetic environment immediately surrounding very compact objects.

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

Fast radio bursts (FRBs) are short, brilliant bursts of radio waves that originate primarily from extragalactic distances.

These phenomena release as much energy in one millisecond as the sun does in 10,000 years, but the physics that cause them are unknown.

Theories range from a highly magnetized neutron star exploded by a stream of gas near a supermassive black hole to proposals whose outburst characteristics match the signature of technology developed by an advanced civilization.

MIT astronomer Kenzie Nimmo and colleagues focused on the event, dubbed FRB 20221022A, in a new study.

This burst was first detected by the Canadian Hydrogen Intensity Mapping Experiment (CHIME) in 2022.

The event occurred in a galaxy about 200 million light years away and lasted about 2 milliseconds.

New research suggests that FRB 20221022A emerged from a region extremely close to the rotating neutron star, up to 10,000 km away.

At such close distances, the burst could have originated from the neutron star's magnetosphere, a highly magnetic region immediately surrounding the microstar.

“In a neutron star environment like this, the magnetic field is actually at the limit of what the universe can produce,” Dr. Nimmo said.

“There has been a lot of discussion about whether this bright radio emission can leak out of that extreme plasma.”

“Atoms cannot exist around these highly magnetic neutron stars, also known as magnetars. They are simply torn apart by the magnetic field,” added astronomer Kiyoshi Masui of the Massachusetts Institute of Technology.

“What's interesting here is that we found that the energy stored in magnetic fields gets twisted and rearranged near the source of the magnetic field and is emitted as radio waves visible on the far side of the universe.”

of findings appear in the diary nature.

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K.Nimo others. 2025. Magnetospheric origin of fast radio bursts confined using scintillation. nature 637, 48-51; doi: 10.1038/s41586-024-08297-w

Source: www.sci.news

Protoplanetary disks surrounding stars similar to the Sun seem to have had a longer lifespan in the early universe

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In 2003, Hubble provided evidence of giant exoplanets around very old stars. Such stars have only small amounts of the heavy elements that make up planets. This suggests that some planetary formation occurred when our universe was very young, and that those planets had time to form and grow large within the primordial disk, becoming even larger than Jupiter. I am. But how? To answer this question, astronomers used the NASA/ESA/CSA James Webb Space Telescope to study stars in the nearby Small Magellanic Cloud, which, like the early Universe, lacks large amounts of heavy elements. They discovered that not only do some stars there have planet-forming disks, but that those disks are longer-lived than the disks found around young stars in our Milky Way galaxy.

This web image shows NGC 346, a massive star cluster in the Small Magellanic Cloud. Yellow circles superimposed on the image indicate the positions of the 10 stars investigated in the study. Image credits: NASA/ESA/CSA/STScI/Olivia C. Jones, UK ATC/Guido De Marchi, ESTEC/Margaret Meixner, USRA.

“With Webb, we have strong confirmation of what we saw with Hubble, and we need to rethink how we model planet formation and early evolution in the young Universe.” European Space Research Agency said Dr. Guido de Marchi, a researcher at Technology Center.

“In the early universe, stars formed primarily from hydrogen and helium, with few heavier elements such as carbon or iron, and were later born from supernova explosions.”

“Current models predict that because heavy elements are so scarce, the lifetime of the disk around the star is short, so short that in fact planets cannot grow,” said a researcher at NSF's NOIRLab's Gemini Observatory. said lead scientist Dr. Elena Sabbi.

“But Hubble actually observed those planets. So what happens if the model is incorrect and the disks have a longer lifespan?”

To test this idea, the astronomers trained Webb in the Small Magellanic Cloud, a dwarf galaxy that is one of the closest galaxies to the Milky Way.

In particular, they examined the massive star-forming cluster NGC 346, which also has a relative lack of heavy elements.

This cluster served as a nearby proxy for studying stellar environments with similar conditions in the distant early universe.

Hubble observations of NGC 346 since the mid-2000s have revealed that there are many stars around 20 to 30 million years old that are thought to still have planet-forming disks around them.

This was contrary to the conventional idea that such disks would disappear after two or three million years.

“Hubble's discovery was controversial and went against not only the empirical evidence for the galaxy, but also current models,” Dr. De Marchi said.

“This was interesting, but without a way to obtain the spectra of these stars, we will not know whether what we are witnessing is genuine accretion and the presence of a disk, or just an artificial effect. I couldn't actually confirm it.”

Now, thanks to Webb's sensitivity and resolution, scientists have, for the first time, spectra of the formation of Sun-like stars and their surrounding environments in nearby galaxies.

“We can see that these stars are actually surrounded by a disk and are still in the process of engulfing material even though they are relatively old, 20 or 30 million years old,” De Marchi said. Ta.

“This also means that planets have more time to form and grow around these stars than in nearby star-forming regions in our galaxy.”

This discovery contradicts previous theoretical predictions that if there were very few heavy elements in the gas around the disk, the star would quickly blow away the disk.

Therefore, the lifespan of the disk is very short, probably less than 1 million years.

But how can planets form if dust grains stick together to form pebbles and the disk doesn't stay around the star long enough to become the planet's core?

The researchers explained that two different mechanisms, or a combination of them, may exist for planet-forming disks to persist in environments low in heavy elements.

First, the star applies radiation pressure to blow the disk away.

For this pressure to be effective, an element heavier than hydrogen or helium must be present in the gas.

However, the massive star cluster NGC 346 contains only about 10 percent of the heavy elements present in the Sun's chemical composition.

Perhaps the stars in this cluster just need time to disperse their disks.

A second possibility is that for a Sun-like star to form when there are few heavier elements, it would need to start with a larger cloud of gas.

As the gas cloud grows larger, it produces larger disks. Therefore, because there is more mass in the disk, it will take longer to blow it away, even if the radiation pressure is acting the same.

“The more material around the star, the longer the accretion will last,” Sabbi says.

“It takes 10 times longer for the disk to disappear. This has implications for how planets form and the types of system architectures that can be used in different environments. This is very exciting.”

of study Published today on astrophysical journal.

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Guido de Marchi others. 2024. Protoplanetary disks around Sun-like stars appear to live longer when they are less metallic. APJ 977,214;Doi: 10.3847/1538-4357/ad7a63

This article is adapted from an original release by the Webb Mission Team at NASA's Goddard Space Flight Center.

Source: www.sci.news

Peak of Geminid Meteor Shower and Shooting Stars Set for Friday night to Saturday

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overview

  • The annual Geminid meteor shower is scheduled to peak Friday night and early Saturday.
  • It is usually one of the best and most reliable meteor showers of the year.
  • Stargazers can also look for Jupiter and three bright star formations known as the Winter Triangle.

Stargazers may have something to look forward to this weekend, as the annual Geminid meteor shower peaks Friday night into early Saturday morning.

The meteor shower has been going on all month, but the number of shooting stars is expected to increase into the weekend, especially after midnight Friday and in the pre-dawn darkness. According to NASA.

The Geminid meteor shower can be seen in the northern and southern hemispheres, but a nearly full moon could wash out some faint shooting stars in this year’s show.

Still, the Geminid meteor shower is typically one of the best and most reliable meteor showers of the year, so when conditions are clear, skywatchers can spot bright meteors streaking the night sky. You can do that.

Under ideal sky viewing conditions, with no bright moonlight and little interfering light pollution, you can see as many as 120 Geminid meteor showers per hour.

The Geminid meteor shower was observed in Mumbai, India on December 14, 2017.
Pratik Chorge / Hindustan Times / Getty Images File

As their name suggests, Geminid meteors appear to stream from the constellation Gemini, but skywatchers should be able to see the shooting stars without looking directly into the constellation.

NASA experts suggest lying on your back with your feet facing south to enjoy the Geminid meteor shower. It is best to choose a dark viewing location, away from city lights and other light pollution.

Unlike most other meteor showers, which are caused by comet debris that has burned up in Earth’s atmosphere, the Geminid meteor shower is the remains of an asteroid known as 3200 Phaethon.

If you’re planning on checking out the meteor shower this weekend, be sure to also look for Jupiter in the night sky. The planet lies between the nearly full moon and the brightest reddish-orange star in the constellation Taurus, called Aldebaran, and is visible to the naked eye.

Meanwhile, all winter long, skywatchers in the Northern Hemisphere also have the chance to spot the Winter Triangle, a three-bright star formation. This celestial triangle, consisting of Sirius in the constellation Canis Major, Procyon in the constellation Canis Minor, and Betelgeuse in the constellation Orion, stands out in the winter sky.

To see the Winter Triangle, first look for the three stars that make up Orion’s distinctive band. A little below and to the left of the belt is Sirius, the brightest star in the night sky. From there Procyon is a little higher and to the left. Betelgeuse can be seen by looking back toward the constellation Orion, and the shoulder of the constellation appears red.

Source: www.nbcnews.com

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

Hubble captures twin stars in R Aquarii binary system

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Astronomers using the NASA/ESA Hubble Space Telescope have created a unique time-lapse of R Aquari's dynamic behavior from observations spanning 2014 to 2023.

The two stars in the R Aquarii binary system are approximately 1.6 billion miles apart. Image credits: NASA / ESA / Matthias Stute / Margarita Karovska / Davide De Martin / Mahdi Zamani / N. Bartmann, ESA, Hubble.

Located 650 light years away, R Aquary is a so-called symbiotic binary, consisting of two stars surrounded by a large, dynamic cloud of gas.

Such binaries contain two stars in an unequal and complex relationship: a white dwarf and a red giant.

In a disturbing act of stellar cannibalism, white dwarfs are stripping material from their larger companions.

Suffering red giants and unstable white dwarfs occasionally eject material in strange eruptions, loops, and trajectories.

“The twisted outflow of stars makes the region look like an out-of-control lawn sprinkler,” Hubble astronomers said in a statement.

“This dramatically shows how the universe redistributes the products of nuclear energy that form deep inside stars and are jetted out into space.”

“Aquarius R belongs to a class of double stars called symbiotic stars,” they added.

“The host star is an aging red giant star, and its companion star is a compact, burnt-out star known as a white dwarf.”

“The red giant star is mira variable It is more than 400 times larger than the Sun. ”

“The expanded monster star pulsates, changes temperature, and changes brightness by a factor of 750 over a period of approximately 390 days.”

“At its peak, the star is blindingly bright, about 5,000 times brighter than the Sun.”

“When the white dwarf comes closest to the red giant star during its 44-year orbit, it gravitationally sucks out hydrogen gas.”

“This material accumulates on the surface of the dwarf star until spontaneous nuclear fusion occurs, causing the surface to explode like a giant hydrogen bomb.”

“After the explosion, the fueling cycle begins again.”

“This explosion causes geyser-like filaments to erupt from the core, forming strange loops and trajectories as the plasma emerges as a streamer.”

“The plasma is twisted by the force of the explosion and guided upwards and outwards by a strong magnetic field.”

“The outflow appears to be folded into a spiral pattern.”

“Plasma is ejecting into space at more than 1.6 million km (1 million miles) per hour, which is fast enough to travel from Earth to the Moon in 15 minutes.”

“The filament glows in visible light because it is energized by intense radiation from the star.”

Source: www.sci.news

The Hubble Space Telescope Discovers a Spiral Galaxy Forming Stars

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of NASA/ESA Hubble Space Telescope It has provided astronomers with a detailed new image of the barred spiral galaxy NGC 5668.

In this image of the barred spiral galaxy NGC 5668, the Hubble Space Telescope was used to survey the area surrounding a Type II supernova event called SN 2004G to study the types of stars that end their lives as supernovae. The color image is composed of near-infrared and visible light observations by the Hubble Space Telescope's Advanced Camera for Surveys (ACS). Two filters were used to sample different wavelengths. The colors are obtained by assigning a different color to each monochromatic image associated with an individual filter. Image courtesy of NASA / ESA / Hubble / C. Kilpatrick.

NGC 5668 It is located in the constellation Virgo and is about 90 million light years away from Earth.

This galaxy, also known as IRAS 14309+0440, LEDA 52018, and UGC 9363, Found It was discovered on April 29, 1786 by German-born British astronomer William Herschel.

NGC 5668 belongs to two galaxy groups: the NGC 5638 group and the NGC 5746 group.

“At first glance, NGC 5668 does not appear to be a remarkable galaxy,” the Hubble astronomers said.

“It has a diameter of about 90,000 light-years and is roughly the same size and mass as our own Milky Way galaxy. It faces almost head-on, revealing open spiral arms made up of irregular, cloud-like patches.”

“One striking difference between the Milky Way and NGC 5668 is that new stars are forming 60 percent faster in this galaxy.”

“This confirms a galaxy with swirling clouds and gas flows, and bad weather that creates the perfect conditions for new star formation.”

Astronomers have identified two main drivers of star formation in NGC 5668.

“First, this high-quality Hubble Space Telescope snapshot reveals a central bar,” the researchers said.

“Although it may appear slightly elliptical rather than truly bar-shaped, it is likely to influence the galaxy's star formation rate, similar to the bar-like structure at the centers of many spiral galaxies.”

“Second, a high-velocity hydrogen gas cloud has been tracked moving perpendicularly between the galaxy's disk and the faint, spherical halo that surrounds it.”

“They are produced by the powerful stellar winds of hot, massive stars, which feed gas into new star-forming regions.”

“The elevated star formation rate in NGC 5668 is accompanied by a corresponding abundance of supernova explosions,” the researchers said.

“It has been discovered three times in our galaxy, in 1952, 1954, and 2004.”

Source: www.sci.news

A Guide on Viewing Shooting Stars

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The annual Perseid meteor shower will peak between Sunday night and dawn on Monday, giving skywatchers around the world the chance to enjoy one of the most spectacular shooting star shows of the year.

The Perseid meteor shower is usually one of the most anticipated stargazing events of the year due to the high incidence of shooting stars. If the weather is good, you may be able to see up to 100 meteors per hour from a dark location.

“Not only is this shower rich in bright meteors and fireballs (the most so far in the world, in fact), it also peaks when it's still warm and comfortable in mid-August,” says Bill Cook, director of the Meteor Environment Office at NASA's Marshall Space Flight Center in Alabama. NASA said in a blog post.

Experts predict that conditions will be favorable for this year's meteor show, especially since the moon will set around 11:30 p.m. local time, meaning bright moonlight will not obscure the shooting stars.

If the weather is good, it's best to choose an unobstructed viewing location under the darkest possible sky, away from city lights and other light pollution.

In the Northern Hemisphere, stargazing is best done between midnight and dawn. NASA recommends giving your eyes about 45 minutes to adjust to the darkness and avoiding looking at bright screens, such as cell phones.

While the peak of the meteor shower is when you'll have the highest chance of seeing meteors, the Perseids have been visible for several weeks and should continue to be visible after this weekend. The meteor shower occurs annually from mid-July to late August.

This occurs as Earth passes through a cloud of dust particles and debris left behind by a comet known as 109P/Swift-Tuttle, which was discovered in 1862. The light streaks are caused when the debris impacts the atmosphere, vaporizes, and leaves a bright trail as it disintegrates.

Source: www.nbcnews.com

Seeing Shooting Stars: A Step-by-Step Guide

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summary

  • The annual Perseid meteor shower has begun, reaching its peak on the night of August 12th.
  • It's typically one of the most dramatic meteor showers of the year, producing a high rate of shooting stars per hour.
  • The Perseid meteor shower occurs when dust particles and debris from a comet known as 109P/Swift-Tuttle burn up in Earth's atmosphere.

One of the best meteor showers of the year is underway, giving you a chance to see shooting stars in the summer night sky.

The annual Perseid meteor shower began on Sunday and will run through late August. This year's meteor shower will peak on the night of August 12 and into the early morning of August 13.

The Perseid meteor shower is one of the most dramatic phenomena due to the high number of bright meteors that appear per hour. At the peak of the meteor shower, up to 100 meteors per hour can be seen from a dark location (weather permitting).

This is a popular event as meteor showers occur in the summer in the Northern Hemisphere, allowing people to enjoy stargazing in warm weather.

Meteors are often called “shooting stars,” but the celestial phenomenon occurs when tiny pieces of debris from outer space burn up in Earth's atmosphere.

The Perseid meteor shower occurs when Earth passes through a cloud of dust particles and debris from a comet known as 109P/Swift-Tuttle, which was discovered in 1862. The streaks of light are produced when pieces of debris impact the atmosphere and vaporize, leaving bright trails as they disintegrate.

The Perseid meteor shower gets its name from the fact that shooting stars appear to stream down from a certain point in the constellation Perseus. According to NASA:The constellation will rise in the northeast, but if conditions are right, meteors should be visible across the entire sky.

In the Northern Hemisphere, the best time to observe the Perseid meteor shower is from around midnight after the moon has set until dawn.

For the best viewing, observers should choose a dark, unobstructed location away from city lights and other light pollution.

Source: www.nbcnews.com

Unraveling the origins of the universe’s first stars

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Recently, the James Webb Telescope (JWST) made a groundbreaking observation of a distant galaxy. These early galaxies challenge our understanding of galaxy formation and the physics of the early universe, appearing as bright, massive, fuzzy red dots.

One of JWST’s latest discoveries is the presence of “Tyrannosaurus Rex” Stars in a distant galaxy. The spectrum of this galaxy indicates a significant amount of carbon, raising questions about the origin of these stars.

These early stars are believed to be massive, unknown entities, and the carbon could be a remnant from their existence.

Early stars are rare because they formed in a pristine environment before the universe was polluted with heavy elements. Star formation was more challenging in this simpler time.

read more:

Stars typically begin as balls of hydrogen gas that undergo nuclear fusion reactions to convert hydrogen into other elements.

Star formation requires cooling and compressing gas to ignite nuclear fusion reactions. Dust plays a crucial role in cooling the gas by absorbing and releasing energy during collisions.

The lack of heavy elements like carbon in the early universe posed a challenge for star formation. The first stars were likely more massive and exploded as supernovae, dispersing heavy elements and enabling the formation of stars like our sun.

Through observations of distant galaxies, JWST is providing insights into the origins of the universe and our place in it.

While we may not see the “space dinosaurs,” studying their remnants helps us understand how their existence paved the way for life on Earth.

read more:

Source: www.sciencefocus.com

Is it possible for liquid water to exist on planets orbiting dwarf stars?

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Denis Villeneuve's sci-fi masterpiece Dune: Part 2 The film hits theaters in the US in spring 2024. The movie follows the power struggles of the noble families of the desert planet Arrakis. But what if humanity had become an empire that spanned thousands of worlds in the distant future, as depicted in the film? Sand Dunes How common are desert planets or planets with no water at all in movies and novels?

In the search for these planets, a good place to start is with the most common stars: astronomers have observed what are called small, faint, cool, reddish stars. Red dwarf They make up most of the stars in the galaxy. Astronomers who study planets around stars other than the Sun estimate that every star has at least one planet. About half of the planets around red dwarfs are small, rocky planets with compositions similar to Earth. On the ground planet. Therefore, the most common type of terrestrial planet is thought to be around a red dwarf star.

For decades, astronomers have thought that red dwarfs are too cold for liquid water to exist on their surfaces. To reach the temperature range needed to support liquid water, planets around cooler stars need to orbit closer to their host stars than planets around hotter ones. But unlike stars like the Sun, which have a constant brightness, red dwarfs are born hotter and brighter than their final state for most of their lives.

The terrestrial planets formed with 15 to 70 times more water than Earth, most of it coming from drifting icy comets. But the heat of the young red dwarf star causes the water on these planets to evaporate, turning from liquid to gas in their atmospheres. In the planet's atmosphere, the intense starlight breaks down the water vapor into oxygen and hydrogen. Photolysis. The heavier oxygen stays on the planet while the lighter hydrogen drifts away, and astronomers estimate that as a result, planets around red dwarf stars lose tens of times as much water as Earth's oceans over their first billion years.

A team of Japanese scientists led by Hiroshi Kawamura challenged the paradigm that planets around red dwarfs should lose all their water in this way. They proposed that two factors could significantly reduce the initial water loss of planets orbiting dwarf stars. First, water is decomposed by the intense light in the planet's atmosphere, but some water is produced in the atmosphere when reactive free hydrogen mixes with hydrogen superoxide. Second, the decomposition of water in the atmosphere produces oxygen gas, which protects the water from further intense light.

Kawamura's team used software called the Photochemical and Radiation Transport Model to Proteus To test whether the planet would lose less water if these two factors were taken into account. The researchers calculated the water loss for an Earth-like planet with a water vapor-filled atmosphere and huge oceans. The planet orbits the dwarf star at a distance about 2% of the distance it orbits around the Sun, relative to TRAPPIST-1, shown in the featured image above. The researchers assumed that the only chemical reaction occurring in the planet's atmosphere is between hydrogen and oxygen. Kawamura and his team ran the model once to see if the results differed from previous studies and how they changed depending on the altitude of the planet's atmosphere.

The team found that the model planet's atmosphere turned out as expected: It had a very high layer of atmosphere, where starlight split water into free hydrogen and oxygen atoms, with the hydrogen escaping into space, and a layer of oxygen gas formed below, reducing the intensity of the starlight at lower altitudes, and the free hydrogen mixed with hydrogen superoxide in a chemical reaction to produce more water.

Ultimately, they calculated that the amount of water lost to space was only about seven times that of Earth's oceans. This means that even if a terrestrial planet started at the low end of the water content range, it could still have eight times as much water as Earth's oceans after its first billion years of existence. The researchers suggested that their findings imply that rather than a galaxy filled with planets with little water, like Earth, the universe could contain worlds with vast oceans orbiting dwarf stars. In other words, future humans are likely to discover Arrakis, but not Caladan. Still, they suggested that future researchers should test planetary water loss models with different atmospheric compositions, alternative cooling processes, and water trapped in the planet's rocks and magma.


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Neutron stars merging form heavy elements, scientists find

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Since the 1920s, Edwin Hubble Ever since it was discovered that the universe is expanding, astrophysicists have been asking themselves the question, “Where does matter come from?” In the Big Bang theory, a possible explanation, not a TV show, astrophysicists propose that the universe began with an explosion, a single hot, dense point expanding, then cooling down to transform from pure energy into solid matter. But that origin story ends with the two smallest elements: hydrogen and helium. Not everything in the universe is made of these two elements, leaving scientists with a new question: “Where does other matter come from?”

The emergence of nuclear physics in the early 20th century gave astronomers their first big clue. Researchers studying stars noted that stars are very bright and require a large source of energy to produce that much light. Nuclear physicists, including Albert Einstein and his famous E = mc2 The equations showed that one of the most powerful sources of energy in the universe is the smashing of smaller atoms together to create larger ones – nuclear fusion. And that's exactly what stars do in the hot, dense regions at their centers, called “nuclear fusion.” coreBut there's a limit to this process in stars — specifically, iron, which is the 26th of the 92 naturally occurring elements. Stars create energy by colliding elements with each other, but elements bigger than iron need to generate more energy than they can give off, which is why elements heavier than iron, like gold and uranium, remain unexplained.

Researchers have discovered the next clue in a massive, bright stellar explosion in the night sky. SupernovaIt turns out that massive stars, more than 10 times the size of the Sun, burn up their accumulated elements to fuse rapidly. These stars not only shine, but also run out of energy to hold themselves together, exploding and scattering their outer layers of elements in all directions. This is a supernova explosion. For decades, astrophysicists thought that heavy elements were created from a chaotic mixture of light elements and free energy. However, careful observation of supernovae has shown that the amount of heavy elements produced in the explosion is less than what is needed to explain the abundance of heavy elements in the universe.

Astrophysicists got the final clue in 2017 when the Laser Interferometer Gravitational-Wave Observatory detected the first binary neutron star (BNS) merger. RaigoThe final stage in the life cycle of a massive star, between 10 and 25 times the mass of the Sun, is Neutron StarDuring this stage, the star's core collapses, and the electrons and protons in atoms get so close together that they fuse into neutrons. Two neutron stars orbiting each other collide, scattering debris into the surrounding galaxy. Researchers propose that this phenomenon could provide the energy and matter needed to fuse heavy elements into the heaviest naturally occurring elements.

Researchers from Peking University and Guangxi University wanted to test whether BNS mergers could produce elements heavier than iron. Because the event is extremely rare, occurring only a few dozen times per year across our galaxy, they couldn't just point their telescopes into space and hope for luck. Instead, they used advanced nuclear physics software to simulate a BNS merger.

The researchers gave their simulations specific initial conditions, such as what atoms were present in the stars when the collision began, the rates of nuclear reactions and decay, the number of electrons mixing, and the sizes of the colliding neutron stars. They then mathematically described how temperature, volume, and pressure relate to matter. Equation of stateIt simulates the effects of the collision and calculates what elements would be formed and released into space.

The team found that these BNS mergers could produce huge amounts of very heavy elements, between 300 and 30,000 times the mass of the Sun, which is 10 to 1,000 times the amount produced by supernovae. The team believes that this result could explain the abundance of heavy elements observed in the Galaxy in relation to other cosmic effects, e.g. Galactic WindHowever, the researchers acknowledged that their findings cannot explain the abundance of all heavy elements, especially those at the lower end of the atomic mass range they studied. They explained that these elements are probably still being created in the cores of collapsing stars, but suggested that future researchers should further test this hypothesis.


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Webb uncovers high levels of hydrocarbons in protoplanetary disks surrounding ultra-low-mass stars

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Very low-mass stars orbit rocky exoplanets more frequently than other types of stars. The composition of these planets is poorly understood, but it is thought to be related to the protoplanetary disk in which they form. In the new study, astronomers used the NASA/ESA/CSA James Webb Space Telescope to investigate the chemical composition of the planet-forming disk around ISO-ChaI 147, a red dwarf star just one-tenth the mass of the Sun. They identified emission from 13 carbon-containing molecules, including ethane and benzene.

This is an artist's impression of a young star surrounded by a disk of gas and dust. Image courtesy of NASA/JPL.

ISO-ChaI 147 It is a red dwarf star with a mass 0.11 times that of the Sun, located about 639 light years away in the constellation Chamaeleon.

The star was observed as part of the MIRI Mid-Infrared Disk Survey (MINDS), which aims to bridge the gap between the chemical composition of the disk and the properties of exoplanets.

These observations provide insight into the environments and fundamental elements for the formation of such planets.

Astronomers discovered that the gas in ISO-ChaI 147's planet-forming region is rich in carbon.

This could be due to carbon being removed from the solid material from which rocky planets form, which could explain why Earth is relatively carbon-poor.

“WEBB has greater sensitivity and spectral resolution than conventional infrared space telescopes,” said Dr Aditya Arabavi, an astronomer at the University of Groningen.

“These observations are not possible from Earth because the radiation is blocked by the atmosphere.”

“So far we have only been able to identify acetylene emissions from this object.”

“But Webb's high sensitivity and spectral resolution allowed us to detect faint emissions from fewer molecules.”

“Thanks to Webb, we now know that these hydrocarbon molecules are not only diverse, but abundant as well.”

The spectrum of ISO-ChaI 147 shows the richest hydrocarbon chemical composition ever observed in a protoplanetary disk, consisting of 13 carbon-containing molecules. Image credit: NASA/ESA/CSA/Ralf Crawford, STScI.

The spectrum of ISO-ChaI 147 is Webb's mid-infrared measuring instrument (MIRI) displays the richest hydrocarbon chemical composition ever observed in a protoplanetary disk, consisting of 13 carbon-containing molecules up to benzene.

This includes the first extrasolar detection of ethane, the largest fully saturated hydrocarbon detected outside the solar system.

Fully saturated hydrocarbons are expected to form from more basic molecules, so detecting them here can give researchers clues about their chemical environment.

Astronomers also detected ethylene, propyne, and methyl radicals in a protoplanetary disk for the first time.

“These molecules have already been detected in our solar system, for example in comets such as 67P/Churyumov-Gerasimenko and C/2014 Q2 (Lovejoy),” Dr. Arababi said.

“It's amazing that we can now see these molecules dancing in the cradle of the planet.”

“This is a completely different environment to how we normally think of planet formation.”

The team note that these results have significant implications for the astrochemistry within 0.1 AU and the planets that form there.

“This is very different to the composition found in disks around solar-type stars, where oxygen-containing molecules (such as carbon dioxide and water) dominate,” said Dr Inga Kamp, also from the University of Groningen.

“This object proves that these are unique classes of objects.”

“It's incredible that we can detect and quantify the amount of a molecule that's well known on Earth, such as benzene, in an object more than 600 light years away,” said Dr Agnes Perrin, an astronomer at the French National Center for Scientific Research.

Team result Published in today's journal Science.

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AM Arabavi other2024. Abundant hydrocarbons present in a disk around a very low-mass star. Science 384, 6700: 1086-1090; doi: 10.1126/science.adi8147

Source: www.sci.news

Physicists suggest that the capture and annihilation of dark matter could reignite dormant neutron stars

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A team of particle physicists from the University of Melbourne, Australian National University, King’s College London, and Fermi National Accelerator Laboratory has discovered that the energy transferred when dark matter particles collide and annihilate inside a cold neutron star. They calculated that the star could be heated rapidly. Previously, this heating was thought to be irrelevant because this energy transfer takes a very long time, in some cases longer than the age of the universe itself.

An artist’s impression of a neutron star.

A number of recent studies have focused on trapping dark matter in neutron stars as sensitive probes of the interaction of dark matter with ordinary matter.

This could potentially be used to test dark matter interactions in a way that is highly complementary to experiments on Earth, especially since dark matter is accelerated to relativistic speeds during a fall into a neutron star. there is.

In some cases, neutron star technology may be able to probe interactions that are difficult or impossible to observe with direct dark matter detection experiments. These include dark matter, which is too light to leave a detectable signal in nuclear recoil experiments, and interactions where non-relativistic scattering cross sections are momentum suppressed.

It was recently pointed out that an isolated old neutron star near the Sun could be heated by the capture of dark matter, increasing its temperature by 2000 K.

Once older than 10 million years, an isolated neutron star is expected to cool to temperatures below this unless reheated by standard matter accretion or internal heating mechanisms.

As a result, observations of local neutron stars may place severe constraints on dark matter interactions. Importantly, neutron stars with temperatures in this range produce near-infrared radiation that could be detected by future telescopes.

“Our new calculations show for the first time that most of the energy is stored in just a few days,” said Professor Nicole Bell from the University of Melbourne, lead author of the study.

“The search for dark matter is one of science’s greatest detective stories.”

“Dark matter makes up 85% of the matter in the universe, but we can’t see it.”

“It doesn’t interact with light. It doesn’t absorb, reflect, or emit light.”

“This means that even if we know it exists, we can’t directly observe it with our telescopes.”

“Rather, its attraction to an object that we can see tells us that it must be there.”

“Predicting dark matter theoretically and observing it experimentally are two different things.”

“Earth-based experiments are limited by the technical challenges of building a large enough detector.”

“But neutron stars act as huge natural dark matter detectors, collecting dark matter over astronomically long timescales, so they are a good place to focus our efforts.”

“Neutron stars form when supermassive stars run out of fuel and collapse,” Professor Bell said.

“They have a similar mass to our sun and are squeezed into a sphere just 20km wide. If they got any denser, they would become black holes.”

“Dark matter is the main type of matter in the universe, but it is very difficult to detect because it interacts very weakly with normal matter.”

“In fact, dark matter is so weak that it can pass straight through the Earth and even the Sun.”

“But neutron stars are different. Because neutron stars are so dense, dark matter particles are much more likely to interact with the star.”

“If dark matter particles collide with neutrons inside a star, they lose energy and become trapped.”

“Over time, this will lead to an accumulation of dark matter within the star.”

“We expect this to cause old, cold neutron stars to heat up to a point where they can be observed in the future, or even cause the star to collapse into a black hole,” said the University of Melbourne doctor. candidate Michael Vilgat, co-author of the study.

“If the energy transfer happens quickly enough, the neutron star will heat up.”

“For this to happen, the dark matter would have to collide within the star many times, transferring more and more of the dark matter’s energy until all the energy is stored in the star.”

“Until now it was unknown how long this process takes, because as dark matter particles become less and less energetic, they become less and less likely to interact again.”

“As a result, it was thought that it would take a very long time to transfer all the energy, in some cases longer than the age of the universe.”

Instead, the researchers calculated that 99% of the energy is transferred in just a few days.

“This is good news, because it means dark matter can potentially heat neutron stars to detectable levels,” Birgat said.

“As a result, observations of cold neutron stars will provide important information about the interactions between dark matter and ordinary matter and shed light on the nature of this elusive matter.”

“If we are to understand the ubiquity of dark matter, it is important to use every technology at our disposal to understand what the hidden matter in our universe actually is.” .”

of study Published in Journal of Cosmology and Astroparticle Physics.

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Nicole F. Bell other. 2024. Thermalization and extinction of dark matter in neutron stars. JCAP 04,006; doi: 10.1088/1475-7516/2024/04/006

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Young stars in the spotlight of the Hubble Space Telescope

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Astronomers using the NASA/ESA Hubble Space Telescope collected information about about 500 stars as part of their research. Young Stars Ultraviolet Heritage Library (ULLYSES) Study as an Essential Standard.

This Hubble image shows a star-forming region containing giant young blue stars in the Tarantula Nebula. Image credits: NASA/ESA/STScI/Francesco Paresce, INAF-IASF Bologna/Robert O'Connell, UVA/SOC-WFC3/ESO.

“We believe the ULLYSES project is revolutionary and will have an impact across astrophysics, from exoplanets to the influence of massive stars on the evolution of galaxies, to understanding the early stages of the evolving universe. ” said Dr. Julia Roman-Duval, leader of the ULLYSES implementation team. She is an astronomer at the Space Telescope Science Institute.

“Apart from the specific purpose of research, stellar data can also be used in the field of astrophysics in ways we cannot yet imagine.”

Dr. Romain Duval and her colleagues studied 220 stars and combined their observations with information on 275 stars from the Hubble archive.

The study also includes data from some of the world's largest and most powerful ground-based telescopes and X-ray space telescopes.

The ULLYSES dataset consists of stellar spectra and includes information about each star's temperature, chemical composition, and rotation.

One of the star types being studied under ULLYSES is an ultra-hot, massive blue star.

They are a million times brighter than the Sun and glow intensely in ultraviolet light that can be easily detected by Hubble. Their spectra contain important information for diagnosing the speed of powerful winds.

The wind drives the evolution of galaxies, producing galactic seeds with the elements necessary for life. These elements are cooked in the star's fusion reactor and injected into space as the star dies.

ULLYSES targeted blue stars in nearby galaxies that are deficient in elements heavier than helium and hydrogen.

“Observations of Ulises are a stepping stone to understanding the first stars and their winds in the universe and how they influence the evolution of young host galaxies,” said Dr. Romain Duval.

Another category of stars in the ULLYSES survey are young stars with less mass than the Sun.

Although it is cooler and redder than the Sun, during its formative years it emits large amounts of high-energy radiation, including bursts of ultraviolet and X-rays.

As they are still growing, they are collecting material from the surrounding planet-forming disks of dust and gas.

Hubble's spectra contain important diagnostic information about the mass-gaining process, including the amount of energy this process releases into the surrounding planet-forming disk and nearby environment.

Intense ultraviolet radiation from young stars influences the evolution of these disks as they form planets and the potential habitability of newborn planets.

The target star is located in a star-forming region near the Milky Way.

The ULLYSES concept was designed by a panel of experts with the aim of using Hubble to provide a conventional set of stellar observations.

“ULLYSES was originally conceived as an observation program using Hubble's high-sensitivity spectrometer,” said Dr. Roman Duval.

“However, this research was greatly enhanced by community-driven complementary observations in collaboration with other ground-based and space-based observatories.”

“By covering such a wide area, astronomers can study the lives of stars in unprecedented detail and develop a more comprehensive picture of the properties of these stars and how they affect their environments. It becomes possible to draw.”

Source: www.sci.news

Planets consumed by billions of stars

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Artist's impression of a planet grazing the surface of a star

K. Miller/R. Hart (California Institute of Technology/IPAC)

It appears that at least one in every 12 stars devours a planet. This is because the star system can easily be destabilized when external objects such as rogueworlds or other stars fly nearby, and the disturbance can shake up the planet's orbit and throw the planet into the star. It is thought that it is.

Huang Liu Researchers from Australia's Monash University investigated how often this happens by observing 91 pairs of stars using some of the world's most powerful telescopes. They selected stars that were most likely to have formed together in a binary. This is because these couples should be formed with the same chemical composition. In doing so, researchers were able to determine whether one of them had swallowed a planet in the past. Doing so would change the planet's composition compared to its binary partner.

They found that about 8 percent of pairs contain one star that has eaten a planet, and show signs of being richer in heavy elements than its twin. Each of these stars appears to have ingested between 1.7 and 8.4 Earth masses of material. This is consistent with previous predictions.

“Our estimates are conservative,” Liu says. “I think the actual percentage may be higher, but it's still probably less than 20% or around 20%.” This can vary depending on where in the galaxy a particular star is born.

Understanding how many stars are eclipsed by planets is a potentially important part of understanding the abundance of life in the universe and our chances of finding it.

“The question is: how many stars and planets behave in ways that are conducive to the development of life?” meridith joyce Member of the research team at the Konkoli Observatory in Hungary. “Knowing how many stars there are and how many host planet stars there are are two parts of the calculation, but we also need to know how many stars are eating those planets.”

topic:

Source: www.newscientist.com

Astronomers discover floating crystals preventing cooling in high-mass white dwarf stars

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Astronomers have proposed a new theory to explain why a mysterious population of white dwarfs has stopped cooling for at least 8 billion years.

This diagram shows a white dwarf and the moon. Image credit: Giuseppe Parisi.

White dwarfs are the remains of stars without a nuclear energy source that gradually cool over billions of years, eventually freezing from the inside out to a solid state.

Recently, it was discovered that a population of frozen white dwarfs maintains a constant brightness for a period comparable to the age of the universe, indicating the existence of an unknown, powerful energy source that inhibits cooling.

“We find that the classical picture that all white dwarfs are dead stars is incomplete,” said astronomer Dr Simon Bruin from the University of Victoria.

“To stop these white dwarfs from cooling, we need some way to generate additional energy.”

“We didn’t know how this happened, but now we have an explanation for this phenomenon.”

The researchers say that in some white dwarfs, the dense plasma inside them doesn’t just freeze from the inside out.

Instead, the solid crystals that form when frozen tend to float because they are less dense than the liquid.

As the crystals float upwards, the heavier liquid moves downwards.

As heavy material is transported toward the star’s center, gravitational energy is released, and this energy is enough to interrupt the star’s cooling process for billions of years.

Dr Antoine Bedard, an astronomer at the University of Warwick, said: “This is the first time this transport mechanism has been observed in any type of star, and it’s very interesting because it’s not every day that a completely new astrophysical phenomenon is discovered.”

“We don’t know why this happens in some stars and not others, but it’s probably due to the star’s composition.”

“Some white dwarfs are formed by the merger of two different stars,” Dr Bruin said.

“When these stars collide to form white dwarfs, the star’s composition changes, allowing the formation of floating crystals.”

White dwarfs are routinely used as an indicator of age, and the cooler a white dwarf is, the older it is considered to be.

However, the extra delay in cooling seen in some white dwarfs means that some stars at certain temperatures may be billions of years older than previously thought.

“This new discovery will not only require a revision of astronomy textbooks, but will also require a reexamination of the processes astronomers use to determine the age of stellar populations,” Dr. Blouin said.

of the team paper Published in today’s diary Nature.

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A. Bedard other. Buoyant crystals stop the white dwarf from cooling. Nature, published online March 6, 2024. doi: 10.1038/s41586-024-07102-y

Source: www.sci.news

86 young stars found to have protoplanetary disks by VLT

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New observations of 86 planet-forming disks provide astronomers with a wealth of data and unique insight into how planets form in different regions of the Milky Way.

A planet-forming disk around a young star and its location in the gas-rich clouds of the constellation Taurus, about 600 light-years from Earth. Scientists observed a total of 43 stars in the Taurus region, all of which are pictured here (although planet-forming disks were detected in only 39 of these targets) ).Image credit: ESO / Galfi other. /Iras.

More than 5,000 exoplanets have been discovered to date, many of them in planetary systems significantly different from our solar system.

To understand where and how this diversity occurs, astronomers need to look at the dust- and gas-rich disks that envelop young stars: the cradles of planet formation. These are most commonly found in the giant gas clouds in which the stars themselves are forming.

As with mature planetary systems, new images from ESO's Very Large Telescope (VLT) show the amazing diversity of planet-forming disks.

“Some of these disks show huge spiral arms, probably driven by a complex ballet of orbiting planets,” said Christian Ginski, an astronomer at the University of Galway.

“Some show rings or large cavities formed by planet formation, while others appear smooth and almost dormant amidst this hustle and bustle of activity,” said Antonio Galfi, an astronomer at the Arcetri Astrophysical Observatory. he added.

The authors studied a total of 86 stars across three different star-forming regions in the Milky Way. Taurus and Chameleon I are both about 600 light-years from Earth, and Orion is a gas-rich cloud about 1,600 light-years from us. It is known as the birthplace of several stars more massive than the Sun.

In the Orion cloud, we found that stars in groups of two or more are less likely to have large disks that form planets.

This is an important result given that, unlike our Sun, most stars in our galaxy have companion stars.

In addition to this, the uneven appearance of the disk in this region suggests that there may be a giant planet embedded within it, which could cause the disk to become distorted or misaligned. there is.

Planet-forming disks can extend to distances hundreds of times the distance between Earth and the Sun, but because of their location hundreds of light-years from us, they appear like tiny needles in the night sky. I can see it.

To observe the protoplanetary disk, astronomers used the VLT's Spectropolarimetric High-Contrast Exoplanet Research Equipment (SPHERE).

Additional data was obtained using VLT's X-SHOOTER instrument, allowing researchers to determine how young the star is and how massive it is.

The Atacama Large Millimeter/Submillimeter Array (ALMA) has helped us understand more about the amount of dust around some stars.

Per Gunnar Vallegord, a PhD student at the University of Amsterdam, said: “The process that marks the beginning of the journey towards the formation of planets and, ultimately, the formation of life in our solar system could not be more beautiful. It's almost poetic that it is.”

The results of this study will be published in three papers. journal astronomy and astrophysics.

Source: www.sci.news

ALMA observes water vapor in young star’s protoplanetary disk

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Water molecules are key components in the formation of planetary systems. Astronomers using the Atacama Large Millimeter/Submillimeter Array (ALMA) have detected water vapor in the disk around the young star HL Taurus, where planets may be forming. Their analysis suggests that the hard lower limit for water vapor availability within the interior 17 astronomical units of the Taurus HL system is 3.7 Earth Oceans.

This ALMA image shows water vapor (blue tints) in the protoplanetary disk around HL Taurus. Near the center of the disk, where young stars live, the environment is hotter and the gas brighter. The red ring is a previous ALMA observation showing the distribution of dust around the star.Image credits: ALMA / ESO / National Astronomical Observatory of Japan / NRAO / Facchini other.

Water molecules are undoubtedly one of the most important molecular species in the entire universe.

Water is a highly efficient solvent, so it played a key role in the emergence of life as we know it on Earth.

For this reason, chemical characterization of exoplanetary atmospheres often focuses on detecting this specific molecule.

Water, formed from common hydrogen and oxygen atoms, is so abundant in both gas and ice form that it plays a fundamental role in the physics of planetary system formation.

Dr Stefano Facchini, an astronomer at the University of Milan, said: “We never imagined that we would be able to image oceans of water vapor in areas where planets are likely to form.”

The HL Taurus system is believed to be less than 100,000 years old and has a radius of about 17.9 billion km. It is located 450 light years away in the direction of the constellation Taurus.

The protoplanetary disk of HL Taurus is unusually large and bright, making it a perfect place to look for signs of planet formation.

New ALMA observations reveal that there is at least three times more water inside the disk than in Earth's entire ocean.

Dr Leonardo Testi, an astronomer at the University of Bologna, said: “It is truly amazing that we can not only detect water vapor 450 light-years from us, but also obtain detailed images and spatially resolve it.” said.

Spatially resolved observations with ALMA allow astronomers to determine the distribution of water in different regions of the disk.

“Participating in such an important discovery of the iconic HL Taurus disk was beyond my expectations given my first research experience in astronomy,'' said Dr. Mathieu Vander Donk, an astronomer at the University of Liege. he said.

Dr Facchini said: “Our recent images reveal that significant amounts of water vapor are present at distances from the star that include gaps where planets may now be forming.” said.

“This suggests that this water vapor could influence the chemical composition of planets that form in those regions.”

“To date, ALMA is the only facility capable of spatially resolving water in cold planet-forming disks,” said Professor Wouter Bremings, an astronomer at Chalmers University of Technology.

ESO astronomer Dr Elizabeth Humphreys said: “It's really exciting to be able to witness first-hand in photographs the ejection of water molecules from icy dust particles.”

“The dust particles that make up the disk are the seeds for planet formation, colliding and clumping together to form even larger bodies orbiting the star.”

“Our findings show how the presence of water influences the development of planetary systems, similar to our own solar system about 4.5 billion years ago,” Dr. Facchini said.

of findings It was published in the magazine natural astronomy.

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S. Facchini other. HL Resolved ALMA observations of water in the inner astronomical unit of the Tau disk. Nat Astron, published online on February 29, 2024. doi: 10.1038/s41550-024-02207-w

Source: www.sci.news

Webb uncovers massive inactive galaxy with mature stars in the ancient cosmos

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The formation of galaxies through the stepwise hierarchical coassembly of baryons and cold dark matter halos is a fundamental paradigm underpinning modern astrophysics and predicts a significant decline in the number of giant galaxies in the early Universe. . Very massive quiescent galaxies have been observed 1 to 2 billion years after the Big Bang. These form between 300 million and 500 million years ago and are very limiting for theoretical models, as only some models can form massive galaxies this early. The spectrum of newly discovered quiescent galaxy ZF-UDS-7329 reveals features typical of much older stellar populations. Detailed modeling shows that the stellar population formed about 1.5 billion years ago, when dark matter halos with sufficient host mass had not yet assembled in the standard scenario. This observation may indicate the existence of an undetected early population of galaxies and potentially large gaps in our understanding of the nature of early stellar populations, galaxy formation, and/or dark matter.

This web image shows ZF-UDS-7329, a rare massive galaxy that formed very early in the universe. Image credit: Glazebrook other., doi: 10.1038/s41586-024-07191-9.

Galaxy formation is a fundamental paradigm underpinning modern astrophysics, and a significant decrease in the number of massive galaxies in the early universe is predicted.

Very large quiescent galaxies have been observed 1 to 2 billion years after the Big Bang, casting doubt on previous theoretical models.

Professor Carl Glazebrook, from Swinburne University of Technology, said: “We have been tracking this galaxy for seven years, observing it for hours with two of the largest telescopes on Earth to find out its age.” Ta.

“But it was too red and too faint to be measured. In the end, we had to go outside Earth and use the web to see its properties.”

“This was truly a team effort, from the infrared sky survey that began in 2010 to identifying this galaxy as an anomaly, and the many hours spent with the Keck Telescope and the Very Large Telescope. But we couldn’t confirm it, and finally, last year, we spent a lot of effort trying to figure out how to process the web data and analyze this spectrum.”

“We are now beyond the realm of possibility to have identified the oldest giant stationary monster deep in the universe,” said Dr Temmiya Nanayakkara, an astronomer at Swinburne University of Technology.

“This pushes the limits of our current understanding of how galaxies form and evolve.”

“The key question now is how do stars form so quickly, so early in the universe, and how do they form at a time when other parts of the universe are forming stars? “What kind of mysterious mechanism could cause it to suddenly stop forming?”

“Galaxy formation is determined primarily by how dark matter is concentrated.”

“The presence of these extremely massive galaxies in the early universe poses significant challenges to our standard model of cosmology.”

“This is because dark matter structures large enough to accommodate these massive galaxies are unlikely to have formed yet.”

“More observations are needed to help us understand how common these galaxies are and how massive they really are.”

“This could open new doors in our understanding of the physics of dark matter,” Professor Glazebrook said.

“Webb continues to discover evidence that massive galaxies form early.”

“This result sets a new record for this phenomenon. It’s very impressive, but it’s just one object. But we want to discover more. If I If we were to do this, it would seriously disrupt our understanding of galaxy formation.”

This finding is reported in the following article: paper Published in this week’s magazine Nature.

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K. Glazebrook other. A huge galaxy that formed stars at z ~ 11. Nature, published online on February 14, 2024. doi: 10.1038/s41586-024-07191-9

Source: www.sci.news

New study reveals hundreds of thousands of young stars in Sagittarius C region with solar mass

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Sagittarius C is located just 300 light-years from Sagittarius A*, the supermassive black hole at the center of the Milky Way.

This image of the Sagittarius C region from ESO's Very Large Telescope includes hundreds of thousands of stars. Image credit: ESO/F. Nogueras-Lara.

The center of the Milky Way is the most prolific star-forming region in the entire galaxy.

But astronomers have discovered only a fraction of the young stars they had expected. There is “fossil” evidence that many more stars than we actually see were born recently.

This is because heading to the center of the Milky Way is not an easy task. Clouds of dust and gas block the light from the star, obscuring visibility.

“On average by volume, the galactic center stands out as the most prolific star-forming environment in the galaxy,” said ESO astronomer Francisco Nogueras Lara.

“Over the past 30 million years, we have witnessed the formation of about 1 million stars.”

“But crowding and high extinction rates have hampered their discovery, and so far only a fraction of the young star's expected mass has been confirmed.”

By studying the stellar population of Sagittarius C, Dr. Lara aimed to detect young stars hidden in the galactic center.

In his research, he analyzed the following data: HAWK-I infrared measuring instrument ESO's Very Large Telescope.

He found that Sagittarius C is much richer in young stars than other regions of the galactic center.

“We found that Sagittarius C contains the solar mass of hundreds of thousands of young stars,” Dr. Lara said.

“We compared our results to a recently discovered population of young stars in Sagittarius B1, located at the opposite end of the nuclear star disk.”

“The young stars in Sagittarius C are estimated to be about 20 million years old and likely represent the next evolutionary step for the slightly younger stars in Sagittarius B1.”

“Our discovery contributes to addressing the discrepancy between the expected number of young stars at the center of galaxies and the number of detected stars, and sheds light on their evolution in this extreme environment.”

“As a secondary result, we discovered that Sagittarius C has a population of intermediate-aged stars (approximately 50% of the mass of stars between 2 billion and 7 billion years old), which is composed of a nuclear stellar disk. It does not exist in the innermost region of the world (which is dominated by stars older than 7 billion years).

“This confirms the existence of an age gradient, driving the formation of an inside-out nuclear star disk.”

of findings appear in the diary astronomy and astrophysics.

_____

F. Nogueras-Lara other. 2024. Hunt young stars at the center of the galaxy. Solar masses of hundreds of thousands of young stars in the Sagittarius C region. A&A 681, L21; doi: 10.1051/0004-6361/202348712

Source: www.sci.news

Hubble spots a group of newly formed stars at the end of a colliding galaxy

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Using the NASA/ESA Hubble Space Telescope, astronomers observed seven interacting galaxies with long tadpole-like tidal tails of gas, dust, and numerous stars. Hubble’s exquisite clarity and sensitivity to ultraviolet light led to the discovery of 425 clusters of newborn stars along these tidal tails. Each cluster contains up to a million newborn blue stars.

As seen in this Hubble image, galaxy AM 1054-325 has been distorted from its usual pancake-like spiral shape into an S-shape by the gravity of its neighboring galaxies. As a result, clusters of newborn stars form along tidal tails stretching across thousands of light years, resembling strings of pearls. Image credit: NASA/ESA/STScI/Jayanne English, University of Manitoba.

Tidal tail star clusters have been known for decades. When galaxies interact, gravitational tidal forces pull out long streams of gas and dust.

Two commonly used examples are antennas and rat galaxy It has elongated finger-like projections.

In a new study, astronomer Michael Rodrak of Randolph-Macon College and his colleagues combined new observational data with archival data to determine the age and mass of the tidal tail cluster.

Researchers discovered that these star clusters are very young, only 10 million years old.

And they appear to be forming at the same rate along a tail that extends over thousands of light years.

“It’s surprising that there are so many young objects in the tail,” said Dr Rodrak, lead author of the paper. paper Published in Royal Astronomical Society Monthly Notices.

“It tells us a lot about cluster formation efficiency.”

“With tidal tails, a new generation of stars will be built that otherwise would not exist.”

Tidal tails look like spiral arms of galaxies extending into space.

The outer part of the arm is pulled like taffy by the gravitational tug of war between a pair of interacting galaxies.

Before the merger occurred, galaxies may have been rich in dusty clouds of hydrogen molecules that simply remained inert.

However, during the encounter, the clouds swayed and clashed.

This compressed the hydrogen and triggered the firestorm of star birth.

“The fate of these strung star clusters is uncertain,” the astronomers said.

“They remain intact under gravity and can evolve into globular clusters that orbit outside the plane of the Milky Way.”

“Alternatively, they could disperse and form a stellar halo around their host galaxy, or be thrown off and become stars that wander between galaxies.”

“This pearly star formation may have been more common in the early Universe, when galaxies were colliding with each other more frequently.”

“These nearby galaxies observed by Hubble are proxies for what happened in the distant past, and are therefore laboratories for studying the distant past.”

_____

michael rodrak other. 2023. Star clusters in tidal dust. MNRAS 526 (2): 2341-2364; doi: 10.1093/mnras/stad2886

Source: www.sci.news

“Curb Your Enthusiasm” Stars Dive into 120 Episodes of Cringe-Worthy Content in This Week’s Top Podcasts

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This week's picks

Late fragment
Wide range of weekly episodes available
This introspective and thoughtful show interviews people in their 80s about politics, religion, sex and money. Its outstanding line-up includes Neil Kinnock, Miriam and Margolyes, and Proulis. The first episode of our latest series is a wide-ranging conversation with humanitarian Terry Waite. This is a thoughtful look at his homelessness situation, his economic situation, and what it was like to spend his five years in chains and in total solitary confinement. Alexi Duggins

drink champion
Wide range of weekly episodes available
If you're looking for a quick listen, the latest episode of this loud, alcohol-filled series isn't for you. But if he has more than three hours to spend in conversation with the likes of Grandmaster Flash and Ludacris (below) with his MC Noah and DJ EFN of Hip Hop, it's a lively laugh into the Golden Age of Hip Hop. It will be a journey filled with. advertisement

Ludacris, Guest of Drink Champs. Photo: Mario Anzuoni/Reuters

real black history
Wide range of weekly episodes available
Francesca Ramsey and Conscious Lee shed light on the lesser-known figures who have shaped black culture beyond Martin Luther King Jr., and engage in many fascinating discussions. The excellent first episode focuses on the women of the Black Panther Party, including Assata Shakur, a fugitive targeted by the FBI who maintains her innocence. Hannah Verdier

hidden 20%
Wide range of weekly episodes available
A neurodivergent mind can lead to great creativity, as evidenced by Seedlip entrepreneur Ben Brunson, who was diagnosed with autism and ADHD as an adult. He currently hosts a podcast to change people's perceptions of his 20% who don't fit the neurotypical classification. Guests including actor Kit Harington, vocal coach Carey Grant, and athlete Adele Tracy will bring their insights. HV

A history of curbing enthusiasm
Wide range of weekly episodes available
After 23 years, the final series of Curb has just begun. That's why two of its stars, Jeff Garlin and Susie Essman, are celebrating with a rewatch podcast that rewinds it all the way to the beginning. In fact, in the first episode, Larry David talks about pre-pilot development. A must-listen for avid fans. Holly Richardson

There's a podcast for that

Mary Robinson, host of Mothers of Invention. Photo: Murdo MacLeod/The Guardian

this week, nima job Our picks for the 5 best podcasts on climate crisisfrom the positive changes we can make as individuals to combat the crisis, to the impact on Indigenous communities.

Pre-drilled
From award-winning investigative journalist Amy Westervelt's exclusive season focusing on Namibia's growing oil reserves to Guyana's oil boom that is creating more economic uncertainty for the general public (not to mention rising sea levels) , which delves into the most pressing issues surrounding the climate crisis. . Amy explores the complexities that arise when a country faces both climate change and poverty simultaneously.

mothers of invention
In this fascinating podcast, Mary Robinson (above), Ireland's first female president, shares the microphone with comedian Maeve Higgins and series producer Timari Kodikara. The all-female case leaves no room for debate as to whether men are primarily responsible for the climate crisis. Each episode spotlights a heroic brown, black, and indigenous woman taking on the challenges facing our planet. The trio also give airtime to concerns young people have about how the climate crisis will affect their future prospects. The show features a wide range of guests, from female climate change activists like Diara Tucano to U.S. Sen. Bernie Sanders.

I'm curious about the climate
If you're feeling confused and unprepared to discuss the climate crisis and its potential impact on your life, this TEDxLondon podcast hosted by Mariam Pasha and Ben Hurst is perfect for you. It's a learning tool. The show demystifies unfamiliar climate terminology, dissects climate issues with expert interviews, celebrates Pride, explores queer ecology, and explores intersex birds and transsexual fish. shed light on the world.

climate of change
Climate of Change doesn't have a huge back catalogue, but its six episodes make for a short and sweet listening experience. Guests include Hollywood veteran Cate Blanchett and clean energy economy entrepreneur Danny Kennedy, as well as Prince William, fashion activist Livia Firth and Don't Look Up director Adam McKay. Appear. Despite highlighting the dire challenges facing our planet, this podcast maintains an optimistic tone while providing insight into the important work being done.

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good together
Hosted by sustainability expert Laura Alexander Wittig, this podcast gives listeners the tools to make a difference in mitigating the climate crisis. In each weekly episode, she learns about terms like “circular economy” and discovers practical tips for incorporating eco-friendly habits into your daily life. Wittig covers a wide range of topics, from sustainable spring cleaning to the environmental impact of her streaming services. If you want to contribute to positive change, this is the perfect podcast to inspire you to channel your inner climate hero.

For more Guardian reporting on the environment and the climate crisis, sign up here to receive the Down to Earth newsletter every Thursday.

Why not try it…

  • collection of memories This production takes you on a journey across Canada, from a Viking-era Norse settlement in Newfoundland to the ruins of a sacred Haida village in Gwaii Harnas. Each episode explores new locations and stories that help us understand our complicated past.

  • Comedians Kiri Pritchard-McLean and Eshild Sears travel across Wales, sampling local food and drink, famous landmarks and talking to local characters. pod of wales.

  • in Small efforts are prohibitedIn , theologian and professor Lee C. Camp, along with guests including actor Martin Sheen, examines what makes a good life possible.

If you want to read the full newsletter, subscribe to receive Listen Here in your inbox every Thursday.

Source: www.theguardian.com

10 of the Biggest Stars in the Universe

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The stars that exist in our universe are definitely huge. In fact, our closest star, the Sun, has a diameter of an astonishing 1.4 million km (865,000 miles), which is large enough to fit 1.3 million Earths within it.

However, within the grand scale of the universe, this is a fairly average size. Although many stars are small, scientists have discovered many cosmic giants that are hundreds of times larger. But what is the largest star in the universe?

Introducing the 10 biggest stars ever known to humanity.

10.HV888

HV 888 is circled in the center of the image. Photo courtesy of ESO/Digitalized Sky Survey 2

HV 888 looks a lot like Clifford the dog, except it is located 163,000 light-years away, and is red and very large.

With a solar radius of 1,374 (our Sun has a solar radius of 1), this scarlet supergiant’s color actually indicates that it is nearing the end of its life. Scientists don’t know exactly when the star will go supernova. It could be today, or the star could continue to burn for millions of more years.

Until then, HV 888 will shine incredibly brightly, about 300,000 to more than 500,000 times brighter than the Sun. In other words, anyone living on one of this star’s possible exoplanets would likely need some pretty bright sunglasses.

9. Ah, Scorpio

Star AH Scorpio. Photo courtesy of ESO/Digitalized Sky Survey 2

AH Scorpii is a red supergiant star found in the constellation Scorpius, hence its name. Although she is 1,411 times larger than the Sun, the star is probably much cooler, with a surface temperature between 3,176.85°C (5750.33°F) and 3,408.85°C (6167.93°F). For comparison, our sun is hot at 5,226.85°C (9380.33°F).In other words, AH Scorpio is still very very hot.

8.CM Velorum

Star CM Verorum. Photo courtesy of ESO/Digitalized Sky Survey 2

CM Bellorum, located in the constellation Vela, is a red star 1,416 times larger than the Sun. However, despite its size, this star is invisible to the naked eye without a telescope. This is partly due to its distance from Earth, which is calculated to be approximately 15,000 light-years away.

7.HD12463

Star HD 12463. Photo credit: ESO/Digitized Sky Survey 2

Not much is known about the star, known as HD 12463, but it is estimated to be 1,420 times larger than the Sun. It is located about 163,000 light-years from us in the Large Magellanic Cloud, a galaxy derived from the Milky Way.

6. VY Canis Major

Star VY Canis Major. Photo courtesy of ESO/Digitalized Sky Survey 2

VY Canis Majoris is an oxygen-rich supergiant star 1,420 times larger than the Sun. It is so large that even traveling at the speed of light, it would take him 6 hours to circumnavigate its surface (try this with the Sun and it would take only 14.5 seconds).

Even if you have the time, I don’t recommend it. The temperature of this star is 3,730°C (6,740°F). It’s also incredibly bright, about 300,000 to 500,000 times brighter than the Sun.

5.HD 269551

Star HD 269551 in the Large Magellanic Cloud. Photo courtesy of ESO/Digitalized Sky Survey 2

HD 269551 may not have the catchiest name in the universe, but it’s still a memorable star for its massive size. Its size has been measured to be 1,439 times that of the Sun.

Like many of the large stars on this list, HD 269551 is highly unstable and nearing the end of its life, and will explode as a supernova within the next few million years (a very short time in the grand scale of the universe) It is expected that

4.RSGC1-F01

Spitzer telescope image of the RSGC1 star cluster, home to RSGC1 F01 and many other massive stars. Photo by NASA/Spitzer Telescope

RSGC1 F01 is located in a star cluster in the Milky Way galaxy in the constellation Scuta. Its size is estimated to be 1,436 to 1,530 times that of the Sun.

Remarkably, if RSGC1-F02 were placed at the center of our solar system, the star’s surface (known as the photosphere) would reach Jupiter’s orbit.

3.WOH 5170

WOH S170 shot with DSS2. Photo courtesy of Eso/Digitalized Sky Survey 2

WOH S170, located in the constellation Leo, is a red star 1,461 times larger than the Sun. Wow, sure.

2.WOH G64

This image shows WOH G64 (circled) in the Large Magellanic Cloud, a satellite galaxy of our Milky Way. Photo courtesy of NASA

WOH G64 is a very large star, 1,540 times the size of the Sun.That’s also very likely very Dusty: Encased in a thick layer of tiny particles about 1 light-year in diameter.

WHO G64 is also a very cool star (literally), with a temperature of 3,100°C (or 5,600°F). Compare this to the surface temperature of the sun. The sun’s surface temperature is a fairly warm 5,226.85°C (9380.33°F).

1. UY spine

Photo courtesy of Eso/Digitalized Sky Survey 2

UY Scuti is the largest star ever observed in the universe. The red supergiant star is 1,708 times the width of the Sun and has a radius of 1.2 billion km (738 million miles). This star is located approximately 9,500 light-years from Earth in the constellation Scutum, near the center of the Milky Way.

Despite its massive size, UY Scutum’s temperature is actually 40 percent colder than the Sun’s 3092°C (1700°F). This is because the star has already used up most of its hydrogen fuel, which produces heat and light. This lower temperature means the star emits a reddish glow.

UY Scuti is also a surprisingly young star, probably only 10 to 20 million years old. It may sound like an exaggeration, but the age of our sun is estimated to be 4.6 billion years. But UY Scuti burns through its fuel so quickly that the star is likely at the end of its life and may only have a few million years left.

It is not clear what happens to UY Scuti at the end of its life cycle. It’s possible that the star could explode in a polar nova (triggering a shock wave that triggers the formation of new stars), but one theory suggests UY Scuti would collapse to form a hotter star.

Star Estimation size (radius)
HV888 956 million km (595 million miles)
Oh, Scorpio 983 million km (611 million miles)
CM Velorum 987 million km (613 million miles)
HD12463 987 million km (613 million miles)
VY Canis Major 987 million km (613 million miles)
HD 269551 1.01 billion kilometers (622 million miles)
RSGC1-F01 1.01 billion km (627 million miles)
WOH S170 1,019 million km (633 million miles)
WOH G64 1,072 million km (666 million miles)
UY spine 1.19 billion km (739 million miles)

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Source: www.sciencefocus.com

2024 Meteor Shower Schedule: Best Times to View Shooting Stars

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Meteor Showers in 2024

Whether you’re a seasoned pro or a casual observer, a good meteor shower is always fun to watch

These occur at the same time every year, but you don’t need expensive equipment to get the most out of them. In fact, you’re better without a telescope. By using just your eyes, you can take in a wider field of view and see more meteors.

Why do meteor showers occur on specific days?

As the Earth orbits the Sun, each year we pass through the same stream of debris left behind by comets and sometimes asteroids. In the case of periodic comets such as the large comet 109P/Swift-Tuttle, which is the parent object of the summer Perseid meteor shower, the stream is replenished each time it passes.

Summarized meteor showers in 2024

In this article, we have summarized all the meteor showers in 2024, their maximum period, and the number of meteors that can be observed.

Learn about constellations

While you wait for that all-important peak night, why not brush up on your constellations with our handy astronomer’s guide for beginners? Having a broad understanding of constellations will help you identify and observe the radiance of each meteor shower. It will help you get the most out of your experience.

Full moon calendar

If you prefer the moon, check out our full moon calendar. All dates, names, and times are compiled into one comprehensive list. It also includes some trivia about the moon.

What is a meteor shower?

A meteor shower is a cascade of meteors, also called shooting stars, that flash across the sky and leave a trail of light in their wake. They occur on certain days every year and can be a spectacular sight if conditions are right.

When is the next meteor shower?

After the quadrant meteor shower in January, Britain’s next major meteor shower will be the Lyrids, followed quickly by Eta Aquarius in April. The peaks of these showers are expected on April 22-23 and May 6, respectively, so mark your calendars.

Meteor Showers in 2024

See below the dates of all 2024 meteor showers, along with peak times and number of meteors seen per hour.

  • quadrant meteor shower

    Active: December 28, 2023 – January 12, 2024
    peak: January 3-4, 2024
    Price/hour: 110
    radiation: Boes
    Parent body: Probably 2003 EH1, but not confirmed yet
    Peak moon illumination: 59-49%

  • Urinidae

    Active: December 17th to 26th
    peak: December 22nd-23rd
    Price/hour: Ten
    radiation: Ursa Minor
    Parent body: Comet 8P/Tuttle
    Peak moon illumination: 61-51%

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Source: www.sciencefocus.com

Spotting the Two Legendary Dog Stars in the January Night Sky: A Guide

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Many dogs have been seen in the night sky, but the most famous is Canis Major, also known as the Great Dog. To locate it, start by finding its master, the constellation Orion, specifically the three bands of stars at the center of that constellation. Extend the line downward and to the left (southeast) to reach the alpha star Sirius in the constellation Canis Major.

Sirius, also referred to as the Dog Star, is relatively close to the sun, 8.6 light years away (a light year is the distance light travels in a year, approximately 10 trillion kilometers).

It is the brightest star in the night sky due to its close proximity to Earth. Its light is affected by atmospheric turbulence, causing flickering and variations in color.

Canis Major represents the dog, with a lively animal imagined as running towards Orion. Sirius appears as a pointed head at the top left (northeast), a distorted rectangular body slanted to the bottom left, and even a small tail, but its appendages and hind legs are very low in the sky when viewed from England. Using binoculars, look below (to the south) of Sirius just below the field of view to find the beautiful open star cluster Messier 41 (M41) inside the dog’s body, if the sky is clear and dark.

How to identify the stars of the Big Dog (Canis Major) and the Little Dog (Canis Minor). – Source: Pete Lawrence

To find Canis Minor, also known as the little dog and relative of Canis Major, look upward (north) from Sirius and to the left (east) to a relatively sparsely populated area of the sky with only one bright star, Procyon. This constellation is not often identified as a dog and is basically formed by only two stars, Procyon and Gomeisa.

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Source: www.sciencefocus.com

Huge Neutron Stars Could Have Cores Composed of Unconfined Quark Matter

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The core of a neutron star contains the highest density of matter in the universe. This highly compressed matter can undergo a phase transition in which nuclear matter dissolves into unconfined quark matter, releasing its constituent quarks and gluons. However, it is currently unknown whether this transition occurs inside at least some physical neutron stars. In a new study, physicists from the University of Helsinki, the University of Stavanger, the Flatiron Institute, and Columbia University quantified this possibility by combining information from astrophysical observations and theoretical calculations.

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

Neutron stars are extreme astrophysical objects containing the densest matter found in the modern universe.

It has a radius of about 10 km (6 miles) and a mass of about 1.4 solar masses.

“A long-standing unresolved question concerns whether the enormous central pressure of a neutron star can compress protons and neutrons into a phase called cold quark matter. In this exotic state, individual protons and neutrons no longer exist. We don’t,” said Professor Aleksi Vuorinen of the University of Helsinki.

“The quarks and gluons that make them up are instead freed from typical color confinement and can move almost freely.”

In a new paper, Professor Vuorinen and colleagues provide the first quantitative estimate of the possibility of a core of quark matter existing inside a massive neutron star.

They showed that quark matter is almost inevitable in the most massive neutron stars, based on current astrophysical observations. The quantitative estimates they extracted put the likelihood in the 80-90% range.

For there to be a small chance that all neutron stars are composed only of nuclear matter, the change from nuclear matter to quark matter must occur through a strong primary phase similar to the phenomenon in which liquid water turns to ice. Must be a metastasis.

This type of rapid change in the properties of neutron star matter could destabilize the star in such a way that even the formation of a tiny quark matter core could cause the star to collapse into a black hole.

An artist's impression of the various layers inside a giant neutron star. The red circle represents a significant amount of quark matter core. Image credit: Jyrki Hokkanen, CSC.

“A key element in deriving the new results is a series of large-scale supercomputer calculations that utilize Bayesian inference, a branch of statistical deduction that estimates the likelihood of various model parameters through direct comparison with observed data. “, the authors explained.

“We demonstrate that the Bayesian component allows us to derive new limits on the properties of neutron star matter, approaching the so-called conformal behavior near the center of the most massive and stable neutron stars.”

Dr. Joonas Nettila from the University of Helsinki added: “It is interesting to see specifically how each new neutron star observation improves the ability to estimate the properties of the neutron star material.” .

“Being able to compare theoretical predictions with observations and constrain the possibility of quark-matter nuclei requires hundreds of supercomputers,” said Jonas Hirvonen, a doctoral student at the Flatiron Institute and Columbia University. “We had to spend tens of thousands of CPU hours.”

“We are very grateful to the Finnish Supercomputer Center CSC for providing us with all the necessary resources.”

of paper It was published in the magazine nature communications.

_____

E.Annara other. 2023. Strongly interacting matter exhibits unconfined behavior in massive neutron stars. Nat Commune 14, 8451; doi: 10.1038/s41467-023-44051-y

Source: www.sci.news

The process of how ancient stars produced elements unattainable by Earth

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Researchers have discovered that ancient stars can produce elements with atomic masses of more than 260, heavier than those found naturally on Earth. This discovery improves our understanding of element formation in stars, particularly through the rapid neutron capture processes (r-processes) that occur in neutron stars. . Credit: SciTechDaily.com

A new study reveals that ancient stars can produce elements heavier than Earth, with atomic masses of more than 260, advancing our understanding of cosmic element formation.

How much do elements weigh? An international team of researchers has found that ancient stars had the ability to produce elements with an atomic mass of more than 260, heavier than any element on the periodic table that occurs naturally on Earth. I discovered that. This discovery deepens our understanding of element formation in stars.

space element factory

We are literally made of star stuff. Stars are elemental factories, where elements are constantly merging or breaking down to create other lighter or heavier elements. When we refer to light or heavy elements, we are talking about their atomic mass. Roughly speaking, atomic mass is based on the number of protons and neutrons in the nucleus. atom of its elements.

The heaviest elements are only known to be produced in neutron stars by rapid neutron capture processes, or r processes. Imagine a single atomic nucleus floating in a soup of neutrons. Suddenly, a bunch of these neutrons attach themselves to the nucleus in a very short time (usually less than a second), causing a change from neutrons to protons inside, and voila! Heavy elements such as gold, platinum, and uranium are formed.

Instability of heavy elements

The heaviest elements are unstable or radioactive and decay over time. One way to do this is through a split called fission.

“If you want to make heavier elements, such as lead or bismuth, you need the R process,” says Ian Roederer, associate professor of physics. north carolina state university and lead author of the study. Mr. Roederer previously attended the University of Michigan.

“We need to add a lot of neutrons very quickly, and the problem is that we need a lot of energy and a lot of neutrons to do that,” Roederer says. “And the best place to find both is at the moment of a person’s birth or death. neutron staror when neutron stars collide and the raw materials for the process are produced.

“We have a general understanding of how the r process works, but the conditions of the process are very extreme,” Roederer says. “We don’t really know how many different sites in the universe generate r-processes, and we don’t know how r-processes end. We also don’t know how many neutrons there are Can you add more? Or how heavy can the elements be? So we looked at the elements produced by nuclear fission in well-studied old stars to find out how heavy these elements are. We decided to see if we could answer some of the questions.”

Identify previously unrecognized patterns

The research team newly investigated the abundance of heavy elements in 42 well-studied stars. milky way. These stars were known to contain heavy elements formed by the r process in earlier generations of stars. By looking more broadly at the amounts of each heavy element found in these stars, rather than individually, as is more common, they identified previously unrecognized patterns.

These patterns indicated that some elements listed near the middle of the periodic table, such as silver and rhodium, were likely remnants of nuclear fission of heavy elements. The research team was able to confirm that the r process can produce atoms with an atomic mass of at least 260 before fission.

“That 260 is interesting because, even in nuclear weapons tests, nothing that heavy has ever been detected in space or in nature on Earth,” Roederer said. “But observing them in space gives us guidance on how to think about models and fission. It also gives us insight into how the rich diversity of elements came about.” may be given.”

For more information on this research, see ‘Incredibly profound’ evidence for nuclear fission throughout the universe.’

Reference: “Elemental abundance patterns in stars show splitting of nuclei heavier than uranium” Ian U. Roederer, Nicole Vassh, Erika M. Holmbeck, Matthew R. Mumpower, Rebecca Surman, John J. Cowan, Timothy C. Beers, Rana Ezzeddine, Anna Froebel, Therese T. Hansen, Vinicius M. Placko, Charlie M. Sakari, December 7, 2023. science.
DOI: 10.1126/science.adf1341

The research was published in the journal Science and was supported in part by the National Science Foundation and the National Aeronautics and Space Administration.

Source: scitechdaily.com

Hubble’s Holiday Globe Reveals 1 Billion Stars, Says NASA

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In this festive Hubble Space Telescope image from NASA and ESA (European Space Agency), the galaxy UGC 8091 resembles a sparkling snow globe filled with a billion stars. Credits: ESA/Hubble, NASA, ESA, Yumi Choi (NSF’s NOIRLab), Karoline Gilbert (STScI), Julianne Dalcanton (Center for Computational Astrophysics/Flatiron Institute, Washington)

Dwarf irregular galaxies are born and dazzling stars are born

Hubble’s colorful snapshots show that the universe always seems to be in the holiday spirit. The dwarf irregular galaxy UGC 8091 is a rich example. A dizzying interplay of matter and energy bubbles up to create a dazzling blue, newborn star that looks like a celebratory string of lights. They are encased in a glowing cocoon of hot pink hydrogen gas. A galaxy is a collection of about 1 billion stars. That sounds like a lot, but it’s one-hundredth of the number of stars in our adult bodies. milky way Galaxy.

This little galaxy came late to the party. The early universe was filled with dwarf galaxies, which eventually merged to form the magnificent spiral galaxies that surround us today. Seven million light-years away, UGC 8091 has only recently begun to display its glittering tapestry.

The Hubble Space Telescope is an iconic symbol of space exploration, launched into orbit in 1990. Hubble revolutionized astronomy by providing unprecedented clarity and deep views of the universe, far beyond the distortions of Earth’s atmosphere. Credit: NASA

Hubble Space Telescope presents a starry sky for Christmas

The billion stars of galaxy UGC 8091 resemble sparkling snow globes during this festival. hubble space telescope Images from NASA and ESA (European Space Agency).

The dwarf galaxy is located in the constellation Virgo, about 7 million light-years from Earth. It is considered an “irregular galaxy” because it does not have a regular spiral or elliptical appearance. Rather, the stars that make up this cluster look more like a tangle of bright string lights than a galaxy.

Some irregular galaxies are entangled due to tumultuous internal activity, while others are formed by interactions with neighboring galaxies. The result is a class of galaxies of varying size and shape, including those whose stars are diffuse and scattered.

A combination of 12 camera filters produced this image using light from the mid-ultraviolet to the red end of the visible spectrum. The red spots are likely interstellar hydrogen molecules, excited by the light from the hot, energetic star and glowing. The other sparkles you see in this image are old star combinations. A diverse array of distant galaxies appears in the background, captured by Hubble’s sharp field of view.

The data used in this image was taken by Hubble’s Wide Field Camera 3 and Advanced Survey Camera from 2006 to 2021.

Among other things, the observing program involved in this image sought to investigate the role that dwarf galaxies billions of years ago played in reheating hydrogen that had cooled after the universe expanded. big bang.

Astronomers are also studying the composition of dwarf galaxies and their stars to uncover evolutionary connections between these ancient galaxies and more modern galaxies like ours.

The Hubble Space Telescope is an international cooperation project between the two countries. NASA And ESA. NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts science operations for Hubble and Webb. STScI is operated for NASA by the Association of Universities for Astronomical Research in Washington, DC.

Source: scitechdaily.com

A cluster of stripped helium stars found in the Magellanic Cloud by astronomers

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Removing the hydrogen-rich layer from a main-sequence star exposes the helium-rich core. Such stripped helium stars are known at high and low masses, but not at intermediate masses, despite theoretical predictions that they should be common. In a new study, astronomers at the University of Toronto and elsewhere used ultraviolet photometry to identify candidates for stripped helium stars in two nearby dwarf galaxies, the Large and Small Magellanic Clouds. We observed 25 such candidate stars using optical spectroscopy. Most of these systems have been shown to be binary systems, with the companion star likely stripping the helium star of its outer hydrogen-rich layer.

An artist’s impression of a large-scale binary system. Image credit: ESO / M. Kornmesser / SE de Mink.

The hydrogen-rich outer layers of massive stars can be removed by interactions with binary companions.

Theoretical models predict that this separation would produce a population of hot helium stars with masses between two and eight times the mass of the Sun, but only one such system has been identified to date.

“This was a very large and noticeable hole. If these stars turn out to be rare, it could affect supernovae, gravitational waves, light from distant galaxies, and our theories for all these different phenomena. The whole framework is wrong,” said Dr Maria Draut, an astronomer at the university. of Toronto.

“This discovery shows that these stars actually exist.”

“In the future, we will be able to perform even more detailed physics on these stars.”

“For example, predictions of how many neutron star mergers we will see depend on the properties of these stars, such as how much material is ejected by stellar winds.”

“In the past, people have estimated it, but now for the first time they will be able to measure it.”

Dr. Drout and her colleagues designed a new study to look at the ultraviolet part of the spectrum, where very hot stars emit most of their light.

Astronomers used data from the Swift Ultraviolet/Optical Telescope to collect the brightness of millions of stars in the Large and Small Magellanic Clouds, the two closest galaxies to Earth.

They developed the first wide-field UV catalog of the Magellanic Clouds and used UV photometry to detect systems with unusual UV emissions indicating the possible presence of stripped stars.

They acquired optical spectroscopy with the Magellan Telescope at the Las Campanas Observatory from 2018 to 2022 and conducted pilot studies on 25 objects.

These stripped stars had high temperatures (60,000 to 100,000 K), high surface gravity, and hydrogen-depleted surfaces. Sixteen stars also showed binary motion.

Drout and his co-authors propose that these stars will eventually explode as hydrogen-depleted supernovae.

These objects, like the gravitational wave-emitting objects detected from Earth by the LIGO experiment, are also thought to be necessary for the formation of neutron star mergers.

In fact, researchers believe that some of the objects in the current sample are neutron stars or stripped stars with black hole companions.

These objects are on the verge of becoming double neutron stars or neutron star and black hole systems that may eventually merge.

“Many stars are part of a cosmic dance with partners, orbiting each other in binary star systems,” says Dr. Bethany Ludwig. He is a student at the University of Toronto.

“They are not solitary giants, but part of a dynamic duo, interacting and influencing each other throughout their lives.”

“Our research sheds light on these fascinating relationships, revealing a universe far more interconnected and active than previously imagined.”

“Just as humans are social beings, stars, especially massive stars, are rarely lonely.”

of result appear in the diary science.

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MR Drought other. 2023. Observed population of intermediate-mass helium stars separated by binaries. Science 382 (6676): 1287-1291; doi: 10.1126/science.ade4970

Source: www.sci.news

The Threat of Cool Star’s Strong Winds to Exoplanets

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Artist’s illustration of a stellar planetary system. You can clearly see the stellar wind orbiting the star and its effect on the planet’s atmosphere.Credit: AIP/ K. Riebe/ J. Fohlmeister, editor

A groundbreaking study reveals that cold stars with strong magnetic fields generate powerful stellar winds, providing important information for assessing the habitability of exoplanetary systems.

A study led by scientists at the Potsdam Leibniz Institute for Astrophysics (AIP) uses cutting-edge numerical simulations to systematically characterize the properties of stellar winds in a sample of cold stars for the first time. Ta. They found that stars with stronger magnetic fields generate stronger winds. These winds create unfavorable conditions for the survival of planetary atmospheres, thus affecting the habitability of these systems.

Cool star classification

The Sun is one of the most abundant stars in the universe, known as “cool stars.” These stars are divided into four categories (F-type, G-type, K-type, and M-type) that differ in size, temperature, and brightness. The Sun is a fairly average star and belongs to category G. Stars that are brighter and larger than the Sun belong to category F, while K stars are slightly smaller and cooler than the Sun. The smallest and faintest star is the M star, also known as a “red dwarf” because of the color in which it emits most of its light.

Solar wind and its effects

Satellite observations have revealed that, apart from light, the sun continuously emits a stream of particles known as the solar wind. These winds travel through interplanetary space and interact with the planets of our solar system, including Earth. The beautiful displays of the Northern Lights near the North and South Poles are actually produced by this interaction. But these winds can also be harmful, as they can erode Earth’s stable atmosphere. Mars.

We know a lot about the solar wind, thanks in part to missions like Solar Orbiter, but the same isn’t true for other cool stars. The problem is that we can’t see these stellar winds directly, so we’re limited to studying their effects on the thin gas that fills the cavities between stars in galaxies. However, this approach has some limitations and can only be applied to a small number of stars. This has encouraged the use of computer simulations and models to predict various properties of stellar winds without the need for astronomer observations.

Pioneering research on the properties of stellar winds

In this regard, in collaboration with Cecilia Garaffo of the Harvard University Center for Astrophysics, doctoral student Judy Chevely of AIP’s Stellar Physics and Exoplanet Division, and scientist Julián D. Alvarado Gomez Dr. Katja Poppenhager, head of the department, assisted. The Smithsonian Institution conducted the first systematic study of the expected stellar wind properties for F, G, K, and M stars.

To this end, they performed numerical simulations using one of the most sophisticated models currently available, driven by the observed large-scale magnetic field distributions of 21 well-observed stars. I used it. The simulations were performed at the AIP and Leibniz-Rechenzentrum (LRZ) supercomputing facilities.

The research team investigated how star properties such as gravity, magnetic field strength, and rotation period affect the properties of the wind in terms of velocity and density. The results include a comprehensive characterization of stellar wind properties across spectral types and, in particular, challenge previous assumptions about stellar wind speeds when estimating associated mass loss rates from observations. This indicates that it needs to be reconsidered.

In addition, the simulations can predict the expected size of the Alfvén surface, the boundary between the stellar corona and the stellar wind. This information is the basis for determining whether planetary systems are affected by strong magnetic star-planet interactions. This interaction can occur when a planet’s orbit enters or is completely embedded in the Alfvén surface of its host star.

Impact on planetary systems

Their findings show that stars with magnetic fields larger than the Sun have faster winds. In some cases, stellar wind speeds can be up to five times faster than the average solar wind speed (typically 450 km/s). The study revealed how strong these stars’ winds are in their so-called “habitable zone,” defined as the orbital distance at which a rocky exoplanet can maintain liquid water on its surface and provide an Earth-like atmospheric pressure. It was evaluated as being strong. They found milder conditions around F- and G-type stars, comparable to those experienced by Earth around the G-type Sun, and increasingly harsh wind environments around K- and M-type stars. discovered. Such intense stellar winds have a strong impact on any atmosphere a planet might have.

Broader implications for exoplanet research

This phenomenon is well documented in heliophysics between rocky planets and the Sun, but not in exoplanetary systems. This requires estimates of stellar winds to assess processes similar to those seen between the solar wind and planetary atmospheres. This study is important from the perspective of habitability, as no information on stellar winds has been known for main-sequence stars F to M until now.

Although the study presented in this paper was performed on 21 stars, the results are general enough to apply to other cool main sequence stars. This study paves the way for future studies of stellar wind observations and their effects on planetary atmosphere erosion.

References: Judy J Chebly, Julián D Alvarado-Gómez, Katja Poppenhäger, and Cecilia Garraffo, “Quantifying the wind properties of cool main-sequence stars,” July 19, 2023. Royal Astronomical Society Monthly Notices.
DOI: 10.1093/mnras/stad2100

Source: scitechdaily.com

A spectacular first photo of a snow leopard captured under the stars

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Looking for ghosts requires special patience. The chances of finding it are low, but doubting means giving up, so keep looking.

This is a technique for tracking snow leopards. Morap Namgair learned that early. He was five years old when he first saw the animal in his remote village of Ulay in Ladakh, India. The area is full of wildlife and is a paradise for aspiring photographers like Molap and his younger brother Stanzin. These big cats are called locally. Shanimmortalized in the BBC series Planet Earth II They were mainly grateful to their father, Norbu, who followed them as a crew member.

Ladakh had just become famous for its sightings, but everything was shut down due to the pandemic. That’s when the brothers vowed to photograph something no one had ever photographed before: a snow leopard under the stars. They hoped the image would highlight the beauty of this mountain region and its apex predator, thereby spurring efforts to conserve both. The region is warming twice as fast as the rest of the world, threatening landscapes and wildlife. The brothers believed that if the outside world could only see what was at stake, that would influence the government’s actions.

They spent months blanketing the area with cameras. However, halfway through the project, Stanzin died of heart disease. Although it was difficult, Morap pushed forward on his own.

Last August, on a 33°C (91°F) day, he climbed a ridge at 4,900 meters above sea level. “What I found on camera was a dream come true,” Morap says. He was bittersweet though. “Buddhism believes in reincarnation. I always look at snow leopards and often think, ‘What would happen if Stan Jin was reincarnated as a snow leopard?’ Perhaps he will stop for a photo or perhaps say hello. Maybe he did.”

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Source: www.newscientist.com

Three new young stars found in the central region of the Milky Way galaxy by astronomers

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According to some researchers, the oldest of these stars is 1.5 billion years old, while the youngest is only 100 million years old. paper Published in Astrophysics Journal Letter.

This infrared image from Hubble shows the Milky Way Core Cluster, the densest and most massive star cluster in our galaxy. Image credit: NASA / ESA / Hubble Heritage Team / STScI / AURA / T. Do & A. Ghez, UCLA / V. Bajaj, STScI.

The center of our Milky Way galaxy is located about 27,000 light-years away in the constellation Sagittarius and is a crowded place.

This region is so dense that it’s equivalent to a million stars crammed into the space between the Sun and Alpha Centauri, 4.3 light-years away.

This nuclear cluster surrounds Sagittarius A*, a 4.3 million solar mass black hole at the center of the galaxy.

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In general, many nuclear star clusters coexist with supermassive black holes, which are found in more than 70% of galaxies with masses greater than 100 million to 10 billion solar masses.

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“In previous work, we hypothesized that these particular stars in the middle of the Milky Way may be unusually young,” said Lund University astronomer Rebecca Forsberg.

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“Now we can confirm this. Our study shows that three of these stars are relatively young, at least as far as astronomers are concerned, ranging in age from 100 million years to about 1 billion years. We were able to determine the age.”

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“This is equivalent to the age of the Sun, which is 4.6 billion years old.”

This panorama shows the central region of the Milky Way galaxy. It builds on previous surveys by NASA’s Chandra X-ray Observatory and other telescopes, and extends Chandra’s high-energy field of view further up and down the galactic plane than previous imaging campaigns. The X-rays from Chandra are orange, green, and violet, indicating different X-ray energies. Radio data from MeerKAT is gray. Image credits: NASA / CXC / UMass / QD Wang / NRF / SARAO / MeerKAT.

In this study, Dr. Forsberg and colleagues used high-resolution data from the Keck II telescope in Hawaii. This Keck II telescope is one of the largest telescopes in the world with a 10 meter diameter mirror.

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For further verification, they measured the amount of iron, a heavy element, in the stars

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This element is important in tracking the development of galaxies. This is because astronomers’ theories about star formation and galaxy development show that the formation of heavy elements increases over time in the Universe, so younger stars contain more heavy elements.

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To determine iron levels, astronomers looked at the star’s spectrum in infrared light. Infrared light is a part of the light spectrum that can more easily illuminate dust-dense parts of the Milky Way compared to optical light.

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Researchers say there is considerable variation in iron levels.

“The very wide spread in iron levels could indicate that the innermost parts of the galaxy are incredibly heterogeneous, or unmixed,” said Dr. Brian Thorsbro, an astronomer at Lund University. Stated.

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“This is something we didn’t expect, and it tells us something not only about what the center of a galaxy looks like, but also about what the early universe looked like.”

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“Personally, I think it’s very exciting that we can now study the galactic center itself at such a detailed level,” Dr. Forsberg said.

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“While these types of measurements have been standard for observations of our own galactic disk, they have been an unattainable goal in more remote and exotic parts of the galaxy.”

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“Studies like this can teach us a lot about how our home galaxy formed and developed.”

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B. Thorsbro other. 2023. The range of old metallicities of stars in nuclear clusters is wide. APJL 958, L18; doi: 10.3847/2041-8213/ad08b1

Source: www.sci.news

The Revealed True Nature of Magellan’s Stars After 50 Years of Exploration

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An artist’s rendition of the Magellanic Star Stream, depicting the Small and Large Magellanic Clouds, the Milky Way’s nearest neighbors, is shown in the diagram. The gaseous Magellanic Stream swirls behind the galaxies, spreading across the southern sky as they move, with 13 red giant stars discovered within the stream.

Astronomers from the Center for Astrophysics at Harvard University and the Smithsonian University have solved a 50-year-old mystery by identifying stars within the Magellanic Stream. The discovery helps reveal the distance to the stream, providing new insights into the history and characteristics of our galaxy and its neighbors.

The study, published in the Astrophysical Journal, showcases the discovery of 13 stars within the stream and their unique characteristics that place them precisely within the mysterious structure. The stars’ distances and chemical compositions offer clues to the formation of the Magellanic Stream and the interactions of the Magellanic Clouds with the Milky Way.

By conducting a spectroscopic analysis of distant Milky Way stars, researchers were able to determine their chemical makeup and velocity, ultimately allowing them to identify stars within the Magellanic Stream. This discovery also sheds light on the origin and gravitational pull of the stream, as well as its potential role in the future formation of new stars within the Milky Way.

The Magellanic Stream, which acts as a supplier of cold neutral gas for the formation of Milky Way stars, also holds valuable insights into the composition of galaxies and the distribution of dark matter. Further study of the stream and additional discoveries of stars are expected to provide more surprises and lead to a deeper understanding of our galaxy’s outer reaches.

Source: scitechdaily.com