Tag Archives: dwarf

Unexpected Shock Wave Discovered Surrounding Nearby White Dwarf Star

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Astronomers utilizing ESO’s Very Large Telescope (VLT) have captured stunning shock waves surrounding the white dwarf star 1RXS J052832.5+283824 (commonly known as RXJ0528+2838). This extraordinary phenomenon challenges existing astrophysical models and has the potential to transform our understanding of stellar evolution.

Image credit: ESO / Iłkiewicz et al. showcasing the shockwave around the white dwarf RXJ0528+2838, captured by the MUSE instrument of ESO’s VLT.

Located approximately 730 light-years away in the constellation Auriga, RXJ0528+2838 orbits the center of the Milky Way, similar to our Sun and other stars.

According to Dr. Noel Castro-Segura from the University of Warwick, “As the white dwarf traverses space, it interacts with interstellar gas, causing a type of shock wave known as a bow shock, which resembles a wave building up in front of a moving ship.”

Interestingly, while bow shocks are typically produced by material expelled from the star, the mechanisms observed in RXJ0528+2838 remain unexplained.

RXJ0528+2838 is part of a binary system, with a sun-like companion star. In such systems, gas is often transferred to the white dwarf, creating an accretion disk. However, this disk appears absent, leading to questions about the source of the observed outflow and the surrounding nebula.

Dr. Simone Scaringi from Durham University expressed: “The fact that a seemingly quiet, diskless system could produce such an impressive nebula was a remarkable surprise.”

Astronomers initially identified an unusual nebula around RXJ0528+2838 through images captured by the Isaac Newton Telescope in Spain, prompting further investigation with the MUSE instrument at VLT.

The size and shape of the bow shock indicate that the white dwarf has been generating significant outflows for over 1,000 years.

Although the exact mechanism for such a prolonged outflow from a diskless white dwarf is still under investigation, scientists speculate that RXJ0528+2838 possesses a strong magnetic field, evidenced by MUSE data.

This magnetic field may funnel material directly from the companion star to the white dwarf, bypassing the formation of an accretion disk.

Dr. Christian Ikiewicz from the Nicolaus Copernicus Astronomical Center remarked, “Our findings indicate that diskless systems can still produce powerful outflows, revealing complex interactions that challenge traditional binary star models.”

While the detected magnetic field can sustain a bow shock for hundreds of years, it only partially accounts for the phenomena observed.

“We’ve uncovered something unprecedented and unexpectedly remarkable,” Dr. Scaringi noted.

For further reading on this groundbreaking discovery, refer to the published paper in the journal Nature Astronomy.

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K. Iwkiewicz et al. Persistent bow shock in a diskless magnetized accreting white dwarf. Nat Astron, published online on January 12, 2026. doi: 10.1038/s41550-025-02748-8

Source: www.sci.news

Hubble Captures Stunning Images of Star-Forming Clouds in Nearby Dwarf Galaxy

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Explore the stunning new image captured by the NASA/ESA Hubble Space Telescope, showcasing a section of the N159 star-forming complex located in the Large Magellanic Cloud, a dwarf galaxy approximately 160,000 light-years away from Earth.

This breathtaking Hubble image portrays N159, a vibrant star-forming complex in the Large Magellanic Cloud. Image credit: NASA / ESA / Hubble / R. Indebetouw.

N159 stands as one of the most colossal molecular clouds within the Large Magellanic Cloud, making it a noteworthy member of our cosmic neighborhood – the Milky Way galaxy.

Positioned at the southwestern edge of the renowned Tarantula Nebula, N159 spans over 150 light-years across.

The newly released Hubble image captures only a fraction of the expansive N159 complex.

“A dense cloud of cold hydrogen gas predominates the scene, creating a complex array of ridges, cavities, and luminescent filaments,” stated Hubble astronomers.

“Within these thick clouds, newly formed stars begin to blaze, their intense radiation illuminating the surrounding hydrogen in a striking crimson hue.”

“The brightest zones signify the presence of hot, massive young stars whose vigorous stellar winds and energetic light reshape the surrounding space.”

“These powerful forces carve out bubble-like formations and hollow cavities within the gas, clearly illustrating the effects of stellar feedback.”

“Dark clouds in the foreground glow thanks to a new star shining from behind.”

“The illuminated clouds and intricate bubbles reveal the dynamic interplay between star formation and the primordial matter from which stars arise, capturing the perpetual cycles of creation and transformation within this neighboring galaxy.”

Source: www.sci.news

Webb Discovers Methane Gas on the Dwarf Planet Makemake

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Astronomers utilizing the NASA/ESA/CSA James Webb Space Telescope have discovered evidence of gaseous methane on the remote dwarf planet Macemeiki. This finding is detailed in a paper published in the Astrophysics Journal Letter. This discovery challenges the conventional perception of Makemake as a stable, frozen entity. Following Pltune, where gas presence was confirmed, it is now only the second Transneptune object to display this characteristic.

Protopapa et al. Methane gas was detected with Makemake using Webb observations (white). A sharp radiation peak near 3.3 microns reveals methane in the gas phase on the surface of Makemake. The continuum model (CYAN) is overlaid for comparison. An observable spectrum above the continuum indicates a gas emission peak. Image credit: S. Protopapa/I. Wong/SWRI/STSCI/NASA/ESA/CSA/WEBB.

Makemake, also referred to as FY9 and (136472), was identified in 2005 by a team of astronomers at the California Institute of Technology, led by Mike Brown.

This planet of War is situated in a region beyond Neptune, home to a small solar system.

Its radius measures approximately 715 km (444 miles), making it a dimmer and slightly smaller body than Pluto.

It takes around 305 Earth years for this dwarf planet to complete one orbit around the Sun.

Previously observed stellar occultations indicated that Makemake likely lacked a significant global atmosphere, although thin atmospheres could not be completely dismissed.

Meanwhile, infrared observations suggested mysterious thermal anomalies and peculiar characteristics of its methane ice, hinting at the possibility of local hotspots and potential outgassing on its surface.

“Makemake is one of the largest and brightest icy worlds in the outer solar system, with its surface predominantly comprised of frozen methane,” stated Dr. Sylvia Protopapa, an astronomer at the Southwest Institute.

“Webb has revealed that methane is also present in the gas phase above the surface, making Makemake an even more intriguing subject of study.”

“This indicates that Makemake is not an inert remnant of the outer solar system; rather, it is a dynamic body where methane ice is actively evolving.”

The detected methane spectral emission is interpreted as solar absorbing fluorescence, which occurs when sunlight is re-emitted after being absorbed by methane molecules.

The research team posited that this could either indicate a tenuous atmosphere in equilibrium with surface ice, akin to Pluto, or more transient activities such as comet-like sublimation or cryovolcanic processes.

Both scenarios are plausible and align with current data, given the signal-to-noise ratios and limited spectral resolution.

“The inclination to connect Makemake’s various spectra with thermal anomalies is compelling, but identifying mechanisms that enable volatile activities remains essential to interpreting these observations cohesively.”

“Future Webb observations at higher spectral resolutions will aid in determining whether methane originates from thin atmospheres or outgassing processes like plumes.”

“This discovery opens up the possibility that Makemake has a very thin atmosphere supported by methane sublimation,” noted Dr. Emmanuel Lelouch, an astronomer at the Paris Observatory.

“Our best model estimates a surface pressure around 40 K (minus 233 degrees Celsius) and about 10 picobars, which is a hundred billion times less than Earth’s atmospheric pressure, indicating a dilute surface pressure about ten billion times that of Pluto.”

“If this hypothesis is validated, Makemake will join a select group of outer solar system bodies where surface mass exchanges are still actively occurring today.”

“Another scenario proposes that methane is being expelled in plume-like eruptions,” Dr. Protopapa added.

“In this case, our model indicates that methane may be released at a rate of several hundred kilograms per second, comparable to the intense water plumes seen on Enceladus, Saturn’s moon, and significantly larger than the faint steam observed on Ceres.”

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Silvia Protopapa et al. 2025. JWST detection of hydrocarbon ice and methane gas on Makemake. apjl in press; Arxiv: 2509.06772

Source: www.sci.news

Dwarf Planet Ceres Might Have Hosted a Lasting Source of Chemical Energy to Support Habitability

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While there is no conclusive evidence of microorganisms on Ceres, recent research bolsters the theory that this dwarf planet may have once harbored conditions conducive to single-cell life.

An illustration of Ceres’ interior, highlighting the movement of water and gas from the rocky core to the saltwater reservoir. Carbon dioxide and methane are chemical energy carriers beneath Ceres’ surface. Image credit: NASA/JPL-Caltech.

Previous scientific data from NASA’s Dawn Mission indicated that bright reflective areas on Ceres’ surface were formed from salt left behind by liquid that seeped from below ground.

A subsequent 2020 analysis identified that this liquid originated from a vast reservoir of subsurface brine.

Additional studies found organic materials in the form of carbon molecules on Ceres. While this alone doesn’t confirm the existence of microbial life, it is a crucial component.

Water and carbon molecules are two fundamental aspects of the habitability puzzle for this distant world.

The latest findings suggest that ancient chemical energy on Ceres could have supported the survival of microorganisms.

This does not imply that Ceres currently hosts life, but if it did, “food” sources are likely to have been available.

In a new study led by Dr. Sam Courville from Arizona State University and NASA’s Jet Propulsion Laboratory, a thermal and chemical model was developed to simulate the temperature and composition within Ceres over time.

They discovered that approximately 2.5 billion years ago, Ceres’ underground oceans possibly maintained a stable supply of warm water with dissolved gases emanating from metamorphic rocks in the rocky core.

The heat originated from the decay of radioactive elements within the planet’s rocky interior, a process typical in our solar system.

“On Earth, when hot water from deep underground interacts with ocean water, it frequently creates a fertility hotspot for microorganisms, releasing a wealth of chemical energy,” stated Dr. Courville.

“Therefore, if Ceres’ oceans experienced hydrothermal activity in the past, it would align well with our findings.”

As it stands, Ceres is not likely to be habitable today, being cooler and having less ice and water than it once did.

At present, the heat from radioactive decay in Ceres is inadequate to prevent water from freezing, resulting in highly concentrated saltwater.

The timeframe during which Ceres was likely habitable ranges from 5 billion to 2 billion years ago, coinciding with when its rocky core peaked in temperature.

This is when warm liquid water would have been introduced into Ceres’ groundwater.

Dwarf planets generally lack the benefit of ongoing internal heating due to tidal interactions with larger planets, unlike Enceladus and Europa, moons of Saturn and Jupiter, respectively.

Thus, the highest potential for a habitable Ceres existed in its past.

“Since then, Ceres’ oceans are likely to be cold, concentrated saltwater with minimal energy sources, making current habitability unlikely,” the authors concluded.

A paper detailing these findings was published today in the journal Advances in Science.

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Samuel W. Courville et al. 2025. Core metamorphosis controls the dynamic habitability of the medium-sized marine world – the case of Ceres. Advances in Science 11 (34); doi: 10.1126/sciadv.adt3283

Source: www.sci.news

Hubble Discovers Remnants of a White Dwarf Merger 130 Light Years Away

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The White Dwarf represents the compact core that forms when stars exhaust their fuel and collapse. These remnants are the ashes of Earth-sized stars, typically about half the mass of the Sun, composed of carbon-oxygen cores surrounded by layers of helium and hydrogen. Utilizing far-ultraviolet data from the NASA/ESA Hubble Space Telescope, astronomers have identified carbon in the atmosphere of the famously large white dwarf WD 0525+526. They also determined that the overall mass of hydrogen and helium in the star’s atmosphere was significantly lower than anticipated based on single-star evolution.

An illustration of a merger with a white dwarf sub-huge star (size without scale) that would have occurred in the past. Image credit: Snehalata Sahu/Warwick University.

WD 0525+526 is located approximately 130 light years away in the constellation Auriga.

With a mass exceeding that of our Sun by 20%, this white dwarf is classified as a super-genocide, and its formation process remains poorly understood.

Typically, such white dwarfs form from the collapse of massive stars. However, Hubble’s UV data indicates that WD 0525+526 has a hydrogen-rich atmosphere originating from its core.

“In optical light, WD 0525+526 appears to be a massive yet typical white dwarf,” remarked Sneharata Saff, an astronomer at the University of Warwick.

“However, the ultraviolet observations from Hubble allowed us to detect faint carbon signatures that optical telescopes could not observe.”

“The presence of a small amount of carbon in the atmosphere suggests that this massive white dwarf is likely the product of a merger between two stars.”

“We also believe that many similar merged remnants may pose as white dwarfs in a predominantly hydrogen atmosphere.”

“Only ultraviolet observations can reveal them to us.”

Typically, hydrogen and helium create dense, barrier-like layers around the white dwarf core, concealing carbon-rich elements.

In a stellar merger, the hydrogen and helium enveloping layers can burn away almost entirely as the stars combine.

The resulting single star possesses a very thin envelope that does not prevent carbon from surfacing, which is precisely what is observed in WD 0525+526.

“We found that the hydrogen and helium layers are around one billion times thinner than those typical of a white dwarf,” noted Antoine Bedard, an astronomer at Warwick University.

“We believe these layers were stripped away during the merger, allowing carbon to manifest on the surface.”

“However, this phenomenon is also unusual, as the carbon present is about 100,000 times less than that found on the surfaces of other merged remnants.”

“Coupled with the star’s elevated temperatures—nearly four times hotter than the Sun—the diminished carbon levels suggest that WD 0525+526 evolves at a much faster pace than previously observed.”

This discovery will aid in understanding the destiny of binary star systems, which are crucial for related phenomena such as supernova explosions.

Alongside the enigma, this significantly hotter star’s carbon migrates to the surface.

Other merged remnants later cool enough for convection to bring carbon to the surface; however, WD 0525+526 remains too hot for this process.

Instead, the author identified a subtle mixing process known as semiconvection, uniquely observed in this White Dwarf.

This mechanism permits small amounts of carbon to gradually ascend into the star’s hydrogen-rich atmosphere.

“Finding conclusive proof of individual white dwarf mergers is rare,” remarked Professor Boris Gensick from Warwick University.

“Yet, ultraviolet spectroscopy enables us to detect these signals early, while carbon remains invisible at optical wavelengths.”

“Because the Earth’s atmosphere filters out UV rays, such observations must be conducted from space—currently, only Hubble is capable of this.”

“As WD 0525+526 continues to evolve and cool, we anticipate more carbon will emerge at the surface over time.”

“For now, this ultraviolet illumination offers rare insights into the early aftermath of stellar mergers.

Survey results are published today in the journal Nature Astronomy.

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S. Saff et al. The remnants of Hot White Dwarfs revealed by ultraviolet detection of carbon. Nature Astronomy Published online on August 6th, 2025. doi:10.1038/s41550-025-02590-y

Source: www.sci.news

Is Planet Nine a Myth? Some Astronomers Believe They’ve Discovered a New Dwarf Planet

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A potential new dwarf planet has been identified at the distant fringes of our solar system, taking approximately 25,000 years to complete one orbit around the Sun.

This celestial object, designated 2017, was discovered by a team from the Advanced Research Institute and Princeton University who were searching for a “Planet 9,” a hypothesized planet larger than Earth that is believed to orbit beyond Neptune. Some astronomers suspect that this elusive Ninth planet could shed light on the peculiar clustering of various objects and other oddities observed in the outer solar system.

While in pursuit of the elusive Planet Nine, researchers instead came across another resident of our cosmic neighborhood.

“It’s similar to the way Pluto was discovered,” remarked Sihao Cheng, a member of the Advanced Research Institute that spearheaded the research team. “This endeavor was a real adventure.”

If validated, the newly found dwarf planet could be what Chen refers to as Pluton’s “extreme cousin.” The findings were published on the Preprint site arXiv and have yet to undergo peer review.

Cheng and his colleagues estimate that 2017 measures approximately 435 miles in diameter.

Dwarf planets are categorized as celestial bodies orbiting the Sun that possess enough mass and gravity to be nearly round, yet unlike typical planets, they do not clear their orbital paths of asteroids and other objects.

Eritayan, a co-author of the study and a graduate student at Princeton University, noted that one fascinating characteristic of 2017 is its highly elongated orbit. At its most distant points from the Sun, it lies over 1,600 times farther than Earth does from the Sun.

The potential dwarf planets were discovered through a meticulous examination of a vast dataset from a Chilean telescope that was scanning the universe for signs of dark energy. By compiling observations over time, the researchers identified moving objects exhibiting clear patterns.

While 2017 may be one of the most distant known objects in the solar system, its discovery suggests that other dwarf planets may exist in that vast region of space.

“We used public data that had been available for some time,” explained Jiaxuan Li, a graduate student and co-author of the research at Princeton University. “It was just hiding in plain sight.”

Li mentioned that the object is currently located near the Sun, necessitating a wait of about a month for researchers to conduct follow-up observations using ground-based telescopes. They also hope to eventually study the object with the Hubble Space Telescope or the James Webb Space Telescope.

In the meantime, Chen stated he remains committed to the quest for Planet Nine. However, new findings may complicate long-held theories about the existence of such a planet.

The hypothesis surrounding Planet Nine suggests that planets several times Earth’s size in the outer solar system might clarify why certain groups of icy objects seem to have unusually clustered orbits.

“Under the influence of Planet Nine, any object lacking a specific orbital geometry would eventually become unstable and be expelled from the solar system,” Yang explained.

Despite 2017’s long orbit leading it away from clustered objects, Yang’s calculations indicate that its path will remain stable for the next billion years.

In essence, if Planet Nine existed, 2017 would not persist. Yet, Yang emphasized that further research is essential, and the discovery of a new dwarf planet candidate does not definitively rule out Planet Nine’s existence.

For one thing, the simulations currently utilize a single hypothetical location for Planet Nine, and scientists do not all agree on the locations of these planets.

Konstantin Batygin, a planetary science professor at the California Institute of Technology, first proposed the existence of Planet Nine in a 2016 study co-authored with Mike Brown from Caltech.

He remarked that the discoveries related to 2017 neither confirm nor deny the theory. Batygin noted that outer solar system objects that might demonstrate gravitational influences of Planet Nine must have their closest points of orbit remain sufficiently distant and not interact significantly with Neptune.

“Unfortunately, this object does not fall into that category,” Batygin told NBC News. “It’s in a chaotic orbit, so the implications are not significant, as it complicates the scenario.”

Batygin expressed excitement about the new research for providing additional context regarding how objects evolve in the outer solar system, praising the researchers’ efforts in mining public datasets as “heroic.”

Chen, however, remains optimistic about finding Planet Nine.

“The entire project commenced as a search for Planet Nine, and I’m still in that mindset,” he remarked. “This, however, is an enthralling tale of scientific discovery. Whether or not Planet Nine exists, the pursuit is a captivating venture.”

Source: www.nbcnews.com

Astronomers Identify Potential Dwarf Planets Orbiting Every 25,000 Years

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The recently identified Transneptunian object, which was named in 2017, stands out as one of the most prominent objects in our solar system, measuring approximately 700 km in diameter, thus qualifying as a dwarf planet.

All cut-out images of 19 detections for 2017 2017. Image credits: Chen et al, arxiv: 2505.15806.

Transneptunian Objects (TNOs) are small celestial bodies that orbit the Sun at distances greater than that of Neptune.

In the 30 years following the discovery of the first TNO outside Pluto, numerous research initiatives have been launched to explore the expansive regions of the outer solar system, resulting in the identification of over 5,000 TNOs to date.

The newly discovered TNO is significant for two main reasons: its unique trajectory and substantial size.

“The object’s aphelion—the furthest point in its orbit from the Sun—is over 1,600 times the distance of Earth’s orbit,” states Dr. Sihao Chen, an astronomer at the Institute of Advanced Research and Boundary Research.

“Conversely, its perihelion—the closest point in its orbit to the Sun—is 44.5 times that of Earth’s orbit, akin to Pluto’s orbit.”

“This extreme trajectory takes around 25,000 years to complete, suggesting a complex gravitational history,” he adds.

“We likely experienced a close encounter with a massive planet, compelling us into this wide orbit,” comments Princeton University astronomer Dr. Elitas Yang.

“There may have been multiple phases in this transition.”

“The object might have initially been ejected into the Oort Cloud, the outermost region of the solar system, which is home to numerous comets.”

“Many extreme TNOs appear to follow similar trajectories, but 2017 OF201 stands out as an anomaly,” remarks Dr. Jiaxuan Li, also from Princeton University.

“This clustering is interpreted as indirect evidence suggesting the presence of another celestial body, often referred to as Planet X or Planet Nine, which could be influencing these objects through gravitational forces.”

“The existence of 2017 OF201 as an outlier in this clustering could potentially challenge this hypothesis.”

Astronomers estimate the diameter of 2017 OF201 to be 700 km, making it the second-largest object on such an extensive orbit.

“2017 OF201 can only be detected about 1% of the time when it is relatively close to us,” Dr. Chen notes.

“The presence of this solitary object implies that there may be around 100 other similar objects with comparable trajectories and sizes.”

Researchers discovered 2017 OF201 as part of an ongoing initiative to identify TNOs and potential new planets in the outer solar system.

The detection involved identifying bright spots in astronomical image databases from the Victor M. Blanco Telescope and the Canada France Hawaii Telescope (CFHT), as well as attempting to trace groups of possible spots that indicate TNO movement across the sky.

Scientists identified 2017 OF201 in 19 different exposures collected over a span of seven years.

“Although advancements in telescopic technology have allowed us to explore distant realms of the universe, much remains to be uncovered within our own solar system,” concludes Dr. Chen.

The team’s paper has been published online at arxiv.org.

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Sihao Cheng et al. 2025. Discovery of new planet candidates in extremely wide orbits: 2017 OF201. arxiv: 2505.15806

Source: www.sci.news

A Newly Discovered Dwarf Planet at the Solar System’s Frontier

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Orbits of the potential dwarf planet known as 2017 OF201 and the dwarf planet Sedna

Tony Dunn

A newly discovered distant dwarf planet lies beyond Neptune, challenging the existence of the hypothetical Planet 9 or Planet X.

Sihao Cheng and colleagues first spotted this object, initially recognized in 2017, while reviewing data from the Victor M. Blanco telescope in Chile.

The 2017 OF201 measures roughly 700 km in diameter, qualifying it as a dwarf planet similar to Pluto, which is about three times larger. Currently, it is positioned approximately 90.5 astronomical units (AU) away from Earth, roughly 90 times the distance from the Earth to the Sun.

Classified as a Trans-Neptunian Object (TNO), 2017 OF201 has an average orbital distance from the Sun that exceeds Neptune’s orbit. It travels beyond Neptune and through the Kuiper Belt, a region of icy bodies on the outskirts of the solar system.

Researchers analyzed 19 observations collected over seven years at the Canada-France-Hawaii Telescope. They determined that the next close approach of 2017 OF201 to the Sun would occur at perihelion, positioned at 44.5 AU, which is reminiscent of Pluto’s orbit. Its furthest point from the Sun lies at about 1600 AU, beyond our solar system.

This distant orbit may have resulted from an encounter with a large planet that ejected the dwarf planet from the solar system, according to researchers.

“This is a fascinating discovery,” says Kevin Napier from the University of Michigan. He explains that objects can interact with various stars in the galaxy as they move beyond our solar system and can also interact within our own solar system.

Many extreme TNO trajectories seem to be converging toward a specific direction, which some interpret as evidence for a hidden ninth planet within the Oort Cloud—a vast shell of icy rocks that surrounds the solar system. The speculation is that the gravitational pull of this ninth planet may be influencing TNOs into specific orbital paths.

However, the trajectory of 2017 OF201 does not align with this observed pattern. “This object is certainly an outlier among the observed clustering,” notes Erita Yang at Princeton University.

Cheng and his team also conducted simulations of object orbits concerning Planet 9. “With Planet 9, objects get ejected over hundreds of millions of years. Without it, they remain stable,” states Napier. “This is not evidence supporting the existence of Planet 9.”

Nevertheless, until more data is available, the matter remains unsettled, according to Cheng. “I hope that Planet 9 is real because it would be even more intriguing.”

This candidate dwarf planet takes approximately 25,000 years to complete its orbit, meaning we detect it for only about 1% of that time. “These objects are faint and very challenging to locate, and their elongated orbits make them visible only when they are near the Sun, resulting in a brief window for observation,” explains Napier.

It is possible that hundreds of such objects exist in the outer solar system. The upcoming Vera C. Rubin Observatory is expected to start operating later this year and may delve deeper into the universe to find more objects like this.

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Source: www.newscientist.com

Astronomers Uncover Polar Ejection Stripping Systems Surrounding Brown Dwarf Pairs

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The recently identified planet orbits a binary system comprising two equal brown dwarf stars positioned at a 90-degree angle from 2mass J15104786-2818174 (hereafter referred to as 2M1510).

This diagram illustrates exoplanets orbiting two brown dwarfs. Image credit: ESO/M. Kornmesser.

Cardiovascular planets represent the realm of diabetes found within a binary star system.

These planets generally have orbits aligned with the planes in which their host stars revolve around one another.

Previously, there were indications that planets might exist in vertical or polar orbits. Theoretically, these orbits were stable, and disc formations observed suggested potential planets around polar orbits of stars.

However, astronomers have now obtained clear evidence of the existence of these polar planets.

“We are thrilled to have played a role in finding robust evidence for this configuration,” stated PhD candidate Thomas Beycroft from the University of Birmingham.

The newly discovered exoplanet, 2M1510B, orbits a unique pair of young brown dwarfs.

These brown dwarfs undergo mutual solar eclipses as viewed from Earth, a characteristic that qualifies them within what astronomers refer to as a binary system.

This configuration is exceptionally rare, marking only the second identified pair of brown dwarfs and the first solar system discovered at a right angle relative to the orbit of its two host stars.

Artist’s impression of the unusual trajectory of 2M1510B around the brown dwarf. Image credit: ESO/L. Calsada.

“The planet revolving around the binary brown dwarfs in a polar orbit is remarkably thrilling,” commented Amalie Triaudo, a professor at the University of Birmingham.

Astronomers discovered 2M1510B by refining the trajectories and physical characteristics of the two brown dwarfs using UV and Visual Echelle Spectroscopy (UVES) at ESO’s Very Large Telescope.

The researchers observed strange forces acting on the trajectory of the brown dwarf, leading to speculation about a unique formation with an unusual orbital angle.

“After considering all plausible scenarios, the only explanation consistent with our data is that the planet within this binary is in polar orbit,” Beycroft noted.

“This discovery was fortuitous, as our observations weren’t initially aimed at studying the composition or orbit of such a planet, making it an exciting surprise,” Professor Triaud explained.

“Overall, I believe this not only showcases our astronomers’ capabilities but also illuminates the possibilities within the intriguing universe we inhabit.”

This image depicts the triple system 2M1510. Image credits: Centre Donna Astromyk destrasbourg/Sinbad/Panstars.

This discovery was made possible due to innovative data analysis developed by Dr. Larita Sylum of Cambridge University.

“We can derive their physical and orbital parameters from the variation in speed between the two brown dwarfs, although these measurements were previously uncertain,” Dr. Sairam remarked.

“This improvement has revealed that the interactions between the two brown dwarfs are intricately influenced.”

Study published in the journal Advances in Science.

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Thomas A. Baicroft et al. 2025. Evidence of polar drainage bulges orbiting a pair of brown dwarfs. Advances in Science 11 (16); doi:10.1126/sciadv.adu0627

Source: www.sci.news

Strange vertical orbits of an exoplanet observed around a binary brown dwarf system

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Impression of the artist in the unusual orbit around the brown dwarf of ExoPlanet 2M1510 (AB)B

ESO/L. Calsada

It was first revealed that a pair of rare stars have equally rare companions, exoplanets that rush into orbit vertically.

Astronomers may think they know what the normal thing is about stars and planets, but they say, “But the universe is very diverse.” Amaury Triaud At the University of Birmingham, UK. He and his colleagues unexpectedly discovered evidence of rare constructs while analyzing data collected by a very large Chilean telescope.

The two stars are brown d stars. This means that they are small and very dim because they cannot maintain fusion and are often referred to as failed stars or subseber ral objects. They follow orbit and continue to cover each other when viewed from Earth. Researchers have previously observed only one brown d-star binary.

Triaud and his colleagues carefully analyzed the new binary system to determine the mass of the stars and their movements, and unexpectedly strange signals were found in the data. Ultimately, the only physical scenario that can explain it is that of a planet-sized object orbiting two stars, following an ellipse perpendicular to the star’s orbit.

Triaud says that vertical orbit is not entirely unheard of, but he and his colleagues never expected to see it in this context. “Brown dwarfs are rare. Brown dwarf pairs are rare. Covering a pair of brown dwarfs is even more unusual and faint, making it difficult to measure,” he says. “That was a surprise. In a system that is ideal and not rare in itself, there is this configuration.”

Twenty years ago, such a structure was considered science fiction, but now it has become a scientific fact. Katherine Brandel At Oxford University. “This is a truly beautiful outcome,” she says. Details of the impending orbit of the two stars make a strong claim that this “harmonograph of the sky” is authentic. By studying how they eat each other, we can identify more details about this unique trio’s moves going forward, Blundell says.

Researchers would like to learn more about the exoplanet named 2M1510(AB)B, but can be compared to a fictional tattoo. Star Warsa desert world orbiting two suns. However, the two suns on the 2M1510(AB)B dimming and get exposed to the surface with something similar to the double dose of moonlight.

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Source: www.newscientist.com

White dwarf binary system linked to irregular radio signals

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Astrophysicists have discovered ILT J110160.52+552119.62, a recently discovered temporary radio source, and that the arrival of that approximately one minute pulse with a periodicity of 125.5 minutes is a red-white, white-white dwarf binary system with orbital periods that match the orbital period observed when two stars are observed when they are engaging.

Artistic illustration showing radioactive pulses emitted by the binary star system: white d star orbit around a red d star. Image credits: Daniëlle Futselaar/Artsource.nl.

In recent years, astronomers have detected radio pulses from sources in the Milky Way that last from seconds to minutes.

These pulses differ from what you would expect from known pulsars that produce pulses on the order of milliseconds.

Furthermore, unlike radiopulsars, these so-called long-term transients (LPTs) are periodic on timescales ranging from minutes to hours.

There have been some hypotheses regarding the origin of these novel pulses, but evidence is scarce.

“There are several highly magnetized neutron stars or magnetores known to exhibit radio pulses in periods of a few seconds,” said Charles Kilpatrick, a northwestern astrophysicist.

“Some astrophysicists also claim that the source is spinning and can emit pulses at regular time intervals, so radio emissions are only shown when the source rotates towards us.”

“I know now that at least some long-term radio transients come from binary.”

“We hope this motivates radio astronomers to localize new classes of sources that could arise from neutron stars or magnetoresistance binaries.”

In their study, Dr. Kilpatrick and colleagues focused on periodic radio signals from transient radio sources designated as ILT J110160.52+552119.62 (ILT J1101+5521);

New imaging techniques were used to detect some of these radio pulses in data collected by low frequency arrays (LOFAR).

Behaving like a large radio camera, the telescope can pinpoint the exact location of the radio source in the sky.

According to the team, the Object is about 1,600 light years away in the Ursa major's constellation.

Follow-up observations with multiple mirror telescopes of 6.5 m diameter in Arizona and the Texas Hobby and Everly telescope showed that the ILT J1101+5521 is not a single flashing star, but two stars that cause pulses together.

A white dwarf in orbit around the two stars, the red war star, brings a common center of gravity into orbit every 125.5 minutes.

Researchers say there are two possibilities for the way stars produce unusually long radio pulses.

Potentially, radio bursts can be emitted from the strong magnetic field of a white dwarf or generated by the interaction of a white dwarf and its stellar companion magnetic field.

However, further observation is required to make this clear.

“Thanks to this discovery, we know that compact objects other than neutron stars can produce bright radio emissions,” says Dr. Kaustub Rajwade, an astronomer at Oxford University.

Discoveries are reported in a paper It's published in the journal today Natural Astronomy.

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I. de Ruiter et al. Sporadicated radio pulses from white dwarf binaries during orbit. Nut AthlonPublished online on March 12, 2025. doi:10.1038/s41550-025-02491-0

Source: www.sci.news

Strange X-ray Emissions from a Remote White Dwarf Destroy a Devastated Exoplanet

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Astronomers may have ultimately solved the problem of what is causing the highly energy x-rays of WD 2226-210, a white dwarf star located in the heart of the Helix Nebula.

The impression of this artist shows an ex faction (left) that has come too close to the white dwarf (right) and torn apart by the power of the tide from the stars. Image credits: NASA/CXC/SAO/M. Weiss.

Helix Nebula It is a so-called planetary nebulae, a late stage of the star that discharges the outer layer of gas and leaves behind what is known as the white dwarf.

In the past decades, the Einstein X-ray Observatory and the Rosatt Telescope have detected highly energy x-rays from the white d star of the Helix Nebula, WD 2226-210.

White dwarfs like the WD 2226-210, just 650 light years away, usually do not emit powerful X-rays.

“They're the best,” said Dr. Sandino Estrada Dorado, an astronomer at the National Autonomous University of Mexico.

“We may finally have found the cause of a mystery that lasted over 40 years.”

Previously, astronomers determined that Neptune-sized planets were in very close orbits around WD 2226-210.

Dr. Estrada Dorado and colleagues conclude that there may have been a planet like Jupiter, even closer to the star.

The besieged planet may have initially managed to hold a considerable distance from the white dwarf, but moved inwards by interacting with the gravity of other planets in the system.

Once it got close enough to the white dwarf, the gravity of the star would have partially or completely tore the planet.

“The mystical signals we've seen can be caused by fragments from the crushed planet falling onto the surface of a white dwarf and being heated to shine with x-rays,” said Dr. Martin Guerrero, an astronomer at the Andalusian Institute of Astronomy.

“If confirmed, this will be the first case of a planet that is considered to be destroyed by the central star of the planet.”

WD 2226-210 is located at the heart of the Helix Nebula. Image credit: NASA/CXC/SAO/UNIV MEXICO/ESTRADA-DORADO et al. /JPL/ESA/STSCI/M. MEIXNER/NRAO/TA RECTOR/ESO/Vista/J. Emerson/K. Arcand.

This study shows that X-ray signals from the white d star remained roughly constant in brightness between 1992, 1999 and 2002.

However, this data suggests that there are subtle and regular changes in the x-ray signal every 2.9 hours, which may provide evidence of planetary ruins very close to the white d star.

The author also considered whether a low-mass star could have been destroyed rather than a planet.

Such stars are roughly the same size as planets like Jupiter, but are much less likely to have been torn apart by larger, white dwarfs.

WD 2226-210 has some similarities between the two other white d stars that are not within the planet's nebula and the X-ray behavior.

It may separate the material from the planet's ally, but it will separate the material in a more sedative way without the planet being destroyed immediately.

Other white dwarfs may have dragged material onto their surfaces from traces of the planet.

These three white d stars can form variables or objects of change in the new class.

“They're the best,” said Dr. Jess Tora, an astronomer at the National Autonomous University of Mexico.

Team's paper It will be published in Monthly Notices from the Royal Astronomical Society.

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S. Estrada-Dorado et al. 2025. Added to WD 2226-210, the central star of the Helix Nebula. mnrasin press; Arxiv: 2412.07863

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

Source: www.sci.news

New study uncovers the potential for Earth-like life to exist near a white dwarf star

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According to a new study from the University of California, Irvine University, white dwarfs are the life of planets that have produced a warmer surface environment than a warmer surface environment formed within a habitable zone or within a habitable zone. It may provide a suitable environment.

The drainage ability to orbit the habitable zone of the white dwarf may have more Clement states to compensate for the cooling and dimming of the host star over time. Image credit: David A. Aguilar/CFA.

This study included the University of California Irvine Astronomer. Aokawa Shield Coworkers compared the climate of the water world with an Earth-like atmosphere composition orbiting in habitable zones of two different types of stars: the white d star and the main sequence K-Dwarf star Kepler-62.

Using a 3D global climate computer model, normally used to study the Earth's environment, they say that despite similar stellar energy distributions, the explanet of the white d star is far more than the Kepler-62 deplanet I discovered it was warm.

“White dwarf stars may emit some heat from residual nuclear activity into the outer layer, but they no longer exhibit fusion at their core,” Dr. Shields said.

“For this reason, we don't take into account much of the ability of these stars to host habitable exoplanets.”

“Our computer simulations suggest that if rocky planets exist in orbit, these planets may have more habitable real estate on their surface than previously thought. ”

The White Dwarf habitable zone is much closer to the stars compared to other star settlements, such as Kepler-62.

The authors emphasized that this would result in a much faster rotation period (10 hours) for the white dwarf exoplanet, and that Kepler 62's exoplanet has a 155-day rotation period.

Both planets can be trapped in synchronous orbits with permanent daysides and permanent nightsides, but the rotation of the super-fast white dwarf planets extends the circulation of clouds around the planet.

The much slower 155-day orbital period of the Kepler-62 planet contributes to large dayside liquid cloud masses.

“Synchronous rotation of exoplanets in habitable zones of normal stars like Kepler 62 creates more cloud covers on Earth's dayside, reflecting incoming radiation away from the Earth's surface. I expect that,'' Dr. Shields said.

“That's usually good for planets orbiting near the inner edge of the star's habitable zone, where you can cool off a bit, rather than losing the ocean in a runaway greenhouse.”

“But for a planet orbiting straight in the middle of a habitable zone, that's not a very good idea.”

“The planet orbiting Kepler-62 has so many clouds that it is covered in clouds, sacrificeing valuable habitable surface area in the process.”

“On the other hand, planets orbiting the white dwarf spin so fast that they hardly have cloudy time during the day, so they retain more heat and work in their advantage.”

Less liquid clouds and the strong greenhouse effect on the Nightside creates a warmer state on the white dwar planet compared to the Kepler-62 planet.

“These results suggest that the once thought to be lifeless, white d star stellar environment could present a new pathway for exoplanet and astrobiology researchers to pursue. I'm doing that,” Dr. Shields said.

“With powerful observational capabilities online to assess exoplanet atmospheres and astrobiology, such as those related to the NASA/ESA/CSA James Webb Space Telescope, we are now studying a whole new class of whole new classes. You can enter a new stage of being. The world around the stars that was previously not announced.”

study It was published in Astrophysical Journal.

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Aokawa L. Seals et al. 2025. Increased surface temperature of the habitable white dwarf world compared to the main sequence exoplanet. APJ 979, 45; doi: 10.3847/1538-4357/AD9827

Source: www.sci.news

Webb’s discovery of brown dwarf candidates hints at first wealthy population outside of the Milky Way

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Astronomers using the NASA/ESA/CSA James Webb Space Telescope detected a population of 64 brown dwarf candidates with masses ranging from 50 to 84 Jupiter masses in the star cluster NGC 602.

This image of NGC 602 includes data from Webb's NIRCam (near-infrared camera) and MIRI (mid-infrared instrument) instruments. Image credits: NASA / ESA / CSA / Webb / P. Zeidler / E. Sabbi / A. Nota / M. Zamani, ESA & Webb.

NGC602 is a very young star cluster, about 200,000 light-years away in the constellation Hydra, about 2 to 3 million years old.

Also known as ESO 29-43, this star resides in the wings of the Small Magellanic Cloud.

NGC 602's local environment closely resembles that of the early Universe, with very low abundances of elements heavier than hydrogen and helium.

The presence of dark clouds of dense dust and the fact that the cluster is rich in ionized gas also suggests the presence of an ongoing star formation process.

Together with the associated HII region N90, which contains clouds of ionized atomic hydrogen, this cluster provides a rare opportunity to examine star formation scenarios under conditions dramatically different from those in the solar neighborhood.

Using Webb, Dr. Peter Zeidler and his colleagues at AURA and ESA were able to detect 64 brown dwarf candidates in NGC 602. This is the first rich population of brown dwarfs to exist outside the Milky Way.

“It is possible to detect objects at such great distances only with incredible sensitivity and spatial resolution in the right wavelength range,” Dr. Zeidler said.

“This has never been possible and will remain impossible from the ground for the foreseeable future.”

“So far, about 3,000 brown dwarfs are known, and they all live in our galaxy,” said Dr. Elena Mangiavakas, also from AURA and ESA.

“This discovery highlights the ability to use both Hubble and Webb to study young star clusters,” said Dr. Antonella Nota, executive director of the International Space Science Institute.

“Hubble showed that NGC 602 hosts very young, low-mass stars, but only Webb can conclusively confirm the extent and significance of substellar mass formation in this cluster. Hubble and Webb are an amazingly powerful telescope duo!”

“Our results are very consistent with the theory that the mass distribution of objects below the hydrogen burning limit is simply a continuation of the stellar distribution,” Dr. Zeidler said.

“They seem to form the same way, they just haven't accumulated enough mass to become full stars.”

NSF astronomer Dr. Elena Sabbi said, “Studying the newly discovered metal-poor young brown dwarfs in NGC 602 will shed light on how stars and planets formed under the harsh conditions in the early universe. We are getting closer to uncovering the secrets of this.” NOIRLab, University of Arizona, Space Telescope Science Institute.

“These are the first substellar objects outside the Milky Way,” Manjavakas said.

“We need to be prepared for new breakthrough discoveries in these new objects.”

of result will appear in astrophysical journal.

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peter zeidler others. 2024. A candidate for a subsolar metallic brown dwarf is discovered in the Small Magellanic Cloud. APJ 975, 18; doi: 10.3847/1538-4357/ad779e

Source: www.sci.news

Understanding the Strange Nature of the First Discovered Brown Dwarf

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Congratulations, you're twins

K. Miller, R. Hart/California Institute of Technology/IPAC

A strange star that has confused researchers for decades now makes sense. It turns out that it is not a single star, but two companion stars.

“Previously, it was thought that this brown dwarf was meaningless. We wondered if we were doing something horribly wrong, or if our models were horribly wrong. I was worried. But no, everything is fine. I just have friends.” timothy blunt at the Space Telescope Science Institute in Maryland.

Now, two research teams have used instruments from the W.M. Keck Observatory in Hawaii and the Very Large Telescope in Chile to solve the mystery of the first brown dwarf.

Brown dwarfs are “failed stars” in that they have too little material and are too hot to sustain nuclear fusion. Instead of shining brightly for thousands of years, they dim in the night sky like planets. The first brown dwarf, called Gliese 229B, was discovered in 1995 and had an inexplicably large mass. Jerry Xuan I worked on one of the studies at the California Institute of Technology.

Gliese 229B is estimated to have about 71 times the mass of Jupiter, and a star born at that size, even if it were as old as the universe, would cool down and become faint enough to see us. That would have never happened, said participant Brandt. One of the research team. This has led some researchers to suggest that Gliese 22B is a very faint pair of stars, but until now there has been no conclusive evidence.

Xuan said this was because two fellow brown dwarfs, Gliese 229Ba and Bb, were unusually close together, and very precise observations were needed to see them both. However, observations by both teams confirmed that they exist separately, orbiting each other every 12 days, and are always about 16 times the distance between Earth and the Moon.

He says that revealing the dual identity of Gliese 229B may be the start of a trend. samuel white book He was part of a research team at the California Institute of Technology. “There are probably a lot of binary systems that have been hiding in front of us all this time,” he says.

Xuan said he has already selected several other brown dwarfs to study more precisely. Brown dwarfs resemble both exoplanets and stars, so understanding how many of them are actually twins could shed light on the formation of these other objects as well. Maybe.

topic:

Source: www.newscientist.com

Hubble Space Telescope focuses on Pegasus dwarf spheroidal galaxy

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The NASA/ESA Hubble Space Telescope captured this stunning image of the Pegasus dwarf elliptical galaxy, a moon of the Andromeda galaxy.

The Pegasus dwarf elliptical galaxy is located about 959,000 light-years away from the Andromeda galaxy. Image credit: NASA / ESA / D. Weisz, University of California, Berkeley / Gladys Kober, NASA and The Catholic University of California.

of Pegasus dwarf spheroidal galaxy It is located about 2.7 million light years away in the constellation Pegasus.

“The Andromeda Galaxy, also known as Messier 31, is the closest large spiral galaxy to the Milky Way and is orbited by at least 13 dwarf moons,” Hubble astronomers said in a statement.

“The Pegasus dwarf spheroidal galaxy is one of these compact galaxies.”

“Dwarf spheroidal galaxies are the faintest and most massive galaxies known,” they explained.

“They tend to have an elliptical shape and a relatively smooth distribution of stars.”

“Dwarf spheroidal galaxies are typically devoid of gas and contain mostly old and intermediate-stage stars, although some have recently undergone a small amount of star formation.”

The Pegasus dwarf spheroidal galaxy, also known as Andromeda VI, was discovered in 1996 in images from the Second Palomar Observatory Sky Survey (POSS II).

“The galaxy is characterised by a low abundance of heavy elements, leaving very little gas needed to form the next generation of stars, although it still has more than many of the dwarf spheroidal galaxies in our Local Group,” the astronomers said.

“Researchers suspect that Andromeda's gravitational field is stripping away star-forming gas, leaving it with insufficient material to form more than a few generations of stars.”

“By comparison, some of the Milky Way's comparable distant dwarf spheroidal companions contain intermediate-age stars, which may be because the Andromeda Galaxy is so massive and extended that its gravitational influence reaches farther.”

“The jury is still out on how dwarf elliptical galaxies form,” they noted.

“Theories include collisions between galaxies that break off smaller pieces, the gravitational influence of larger galaxies on small, disk-like dwarf galaxies, and processes related to the birth of small systems among dark matter aggregates.”

“Andromeda and the Milky Way are the only galaxies close enough for astronomers to observe these faint satellite galaxies, so clues to their formation come from nearby galaxies like this one.”

“Hubble studied this galaxy as part of a survey of the entire Andromeda moon system to investigate important topics such as dark matter, reionization, and the growth of galactic ecosystems through the ages of the universe.”

Source: www.sci.news

Discovery of Ancient Dwarf Penguin “Pacdiptes hakataramea” in New Zealand

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Pakdipthes hakataramea Body size would have been similar to that of modern humans Little Blue Penguin (Eudyptula minor)It is approximately 40-45 cm (15.7-17.7 in) in length.

Artist image Pakdipthes hakatarameaPhoto courtesy of Tatsuya Niimura / Ashoro Museum of Paleontology

Pakdipthes hakataramea It lived in New Zealand about 24 million years ago (Late Oligocene Epoch).

This new species was very small, about the size of a little blue penguin. World's smallest — They have anatomical adaptations that allow them to dive.

“Pakdipthes hakataramea “This fossil fills the morphological gap between modern and fossil penguins,” said Dr. Tatsuro Ando, ​​a paleontologist at the Ashoro Museum in Ashoro Town.

“In particular, the shape of the wing bones is very different, and it was unclear how penguins' wings acquired their current shape and function.”

“The humerus and ulna show how penguins' wings evolved.”

“To my surprise, Pakdipthes hakataramea It was very close to the condition of modern penguins, but the elbow joint was very similar to that of older types of fossil penguins.

“Pakdipthes hakataramea This is the first penguin fossil to be found in this combination and is a key fossil that will shed light on the evolution of penguins' wings.”

Fossilized remains Pakdipthes hakataramea The fossils were discovered by palaeontologists Craig Jones and Professor Euan Fordyce during a series of field expeditions in the Hakataramea Gorge in South Canterbury in 1987.

“Analysis of internal bone structure compared with data from modern penguins shows that these penguins had microanatomical features indicative of diving behaviour,” said Dr Carolina Lock, a palaeontologist at the University of Otago.

Modern penguins have excellent swimming abilities, thanks mainly to their dense, thick bones that provide them with buoyancy when diving.

in Pakdipthes hakatarameaAlthough the medullary cavity containing the bone marrow was open, the cortical bone was quite thick, similar to that seen in modern little blue penguins, which tend to swim in shallow waters.

ability Pakdipthes hakataramea Their ability to dive and swim depends on a unique combination of bones.

“Penguins evolved rapidly from the late Oligocene to the early Miocene. Pakdipthes hakataramea “This is a significant fossil from this period,” Dr Locke said.

“Their small body size and unique bone combination may have contributed to the ecological diversity of modern penguins.”

Discovery Pakdiptes hakataramea teeth, paper In Journal of the Royal Society of New Zealand.

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Tatsuro Ando othersA new small penguin fossil discovered from the Late Oligocene of New Zealand and morphofunctional changes in penguin wings. Journal of the Royal Society of New ZealandPublished online July 31, 2024, doi: 10.1080/03036758.2024.2362283

Source: www.sci.news

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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Source: sciworthy.com

Cool brown dwarf emits methane detected by Webb

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Astronomers using the NASA/ESA/CSA James Webb Space Telescope detected methane emissions from the. CWISEP J193518.59-154620.3 (W1935 for short) is an isolated brown dwarf star with a temperature of about 482 K. Their findings also suggest that W1935 could produce auroras similar to those seen on our planet, Jupiter, and Saturn.

Artist's impression of the brown dwarf W1935. Image credit: NASA/ESA/CSA/L. Hustak, STScI.

W1935 is located about 47 light-years away in the constellation Sagittarius.

This brown dwarf was co-discovered by Backyard Worlds: Planet 9 citizen science volunteer Dan Caselden and NASA's CatWISE team.

W1935's mass is not well known, but it is probably in the range of 6 to 35 times the mass of Jupiter.

After observing numerous brown dwarfs observed by Webb, Dr. Jackie Faherty Researchers at the American Museum of Natural History found W1935 to be similar, with one notable exception. It was emitting methane, which had never been seen before in brown dwarfs.

“Methane gas is expected to be present in giant planets and brown dwarfs, but we typically see it absorbing light rather than absorbing it,” Faherty said.

“At first we were confused by what we were seeing, but eventually it turned into pure excitement when it was discovered.”

Computer modeling provided another surprise. W1935 may have a temperature inversion, a phenomenon in which the atmosphere becomes warmer as altitude increases.

Temperature inversions easily occur in planets orbiting stars, but brown dwarfs are isolated and have no obvious external heat source.

“We were pleasantly shocked when the model clearly predicted a temperature inversion,” said Dr Ben Burningham, an astronomer at the University of Hertfordshire.

“But we also needed to figure out where that extra upper atmosphere heat was coming from.”

To find out, astronomers turned to our solar system. In particular, they focused on the study of Jupiter and Saturn. Both show methane release and temperature inversions.

Since the aurora is likely the cause of this feature on the solar system's giants, the researchers speculated that they had discovered the same phenomenon in W1935.

Planetary scientists know that one of the main drivers of Jupiter and Saturn's auroras are high-energy particles from the sun that interact with the planets' magnetic fields and atmospheres, heating the upper layers.

This is also the reason for the aurora borealis we see on Earth. Auroras are most unusual near the poles, so they are commonly referred to as aurora borealis or southern lights.

However, W1935 does not have a host star, so solar wind cannot contribute to the explanation.

There's another fascinating reason why auroras occur in our solar system.

Both Jupiter and Saturn have active moons that occasionally eject material into space, interacting with the planets and enhancing the auroral footprints of those worlds.

Jupiter's moon Io is the most volcanically active world in the solar system, spewing fountains of lava tens of miles high. Also, Saturn's moon Encereadus spews water vapor from geysers that freeze and boil as soon as they reach space.

Although more observations are needed, researchers speculate that one explanation for W1935's aurora may be an active moon that has yet to be discovered.

“Every time astronomers point an object at the Webb, new and surprising discoveries can occur,” Dr. Faherty said.

“When we started this project, we weren't concerned about methane emissions, but now that we know that methane emissions can exist and the explanations are very attractive, we're always paying attention. That's part of how science moves forward.”

a paper The survey results were published in a magazine Nature.

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JK Faherty other. 2024. Methane emission from cool brown dwarfs. Nature 628, 511-514; doi: 10.1038/s41586-024-07190-w

Source: www.sci.news

Blue Compact Dwarf Galaxy: Low Metallicity and Rapid Star Formation in Web Image

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Astronomers using NASA/ESA/CSA’s James Webb Space Telescope have discovered a typical extremely metal-poor, star-forming, blue, compact dwarf galaxy in the constellation Ursa Major, I. Zwicki 18 (abbreviated). I took a stunning image of I Zw 18).

This web image shows I Zwicky 18, a blue, compact dwarf galaxy about 59 million light-years away in the constellation Ursa Major. I Zwicky 18’s nearby companion galaxy can be seen at the bottom of the image. This companion star may be interacting with the dwarf galaxy and may have triggered the galaxy’s recent star formation. Image credits: NASA / ESA / CSA / Webb / Hirschauer other.

I Zw 18 It is located approximately 59 million light years away in the constellation Ursa Major.

This galaxy, also known as Mrk 116, LEDA 27182, and UGCA 166, discovered It was discovered in the 1930s by Swiss astronomer Fritz Zwicky.

At only 3,000 light years in diameter, it is much smaller than our own Milky Way galaxy.

I Zw 18 has experienced several bursts of star formation and has two large starburst regions at its center.

The wispy brown filaments surrounding the central starburst region are bubbles of gas heated by stellar winds and intense ultraviolet light emitted by hot, young stars.

“Metal-poor star-forming dwarf galaxies in the local universe are close analogs of high-redshift dwarf galaxies,” said Dr. Alec Hirschauer of the Space Telescope Science Institute and colleagues.

“Because the history of enrichment of a particular system tracks the accumulation of heavy elements through successive generations of stellar nucleosynthesis, low-abundance galaxies are likely to be more likely to be affected by a common phenomenon in the early Universe, including the global epoch of peak star formation. It mimics the astrophysical conditions where most of the cosmic star formation and chemical enrichment is expected to have taken place.”

“Thus, at the lowest metallicities, we may be able to approximate the star-forming environment of the time just after the Big Bang.”

“I Zw 18 is one of the most metal-poor systems known, with a measured gas-phase oxygen abundance of only about 3% of solar power production,” the researchers said. added.

“At a distance of 59 million light-years and with global star formation rate values ​​measured at 0.13 to 0.17 solar masses per year, this laboratory is designed to support young stars in an environment similar to the one in which they were discovered. It’s an ideal laboratory for studying both the demographics and the demographics of stars that evolved in the very early days of the universe.”

Dr. Hirschauer and his co-authors used Webb to study the life cycle of I Zw 18 dust.

“Until now, it was thought that the first generation of stars began forming only recently, but the NASA/ESA Hubble Space Telescope found “The dimmer and older red stars in the galaxy suggest that their formation began at least 1 billion years ago, and possibly 10 billion years ago,” the researchers said.

“Therefore, this galaxy may have formed at the same time as most other galaxies.”

“New observations by Webb reveal the detection of a set of dust-covered evolved star candidates. They also provide details about Zw 18’s two main star-forming regions. To do.”

“Webb’s new data suggests that major bursts of star formation in these regions occurred at different times.”

“The strongest starburst activity is now thought to have occurred more recently in the northwestern lobe of the galaxy compared to the southeastern lobe.”

“This is based on the relative abundance of young and old stars found in each lobe.”

of findings will be published in astronomy magazine.

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Alec S. Hirschauer other. 2024. Imaging I Zw 18 with JWST: I. Strategy and first results for dusty stellar populations. A.J., in press. arXiv: 2403.06980

Source: www.sci.news

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

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New Study Suggests Photons from Dwarf Galaxies Helped Reionize the Early Universe

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Reionization of the universe happened about 500 million to 900 million years after the Big Bang. This represents the transformation of neutral hydrogen into an ionized gas and marks the end of the “Dark Ages” in the history of the universe. Currently, astronomers using the NASA/ESA/CSA James Webb Space Telescope have obtained spectra of eight ultrafaint dwarf galaxies that existed less than a billion years after the Big Bang. Their observations could help settle long-standing scientific debates about the driving force of reionization and could also be essential to understanding the formation of the first galaxies.

Astronomers estimate that 50,000 near-infrared sources are represented in the Webb image of galaxy cluster Abel 2744. Image credits: NASA / ESA / CSA / I. Labbe, Swinburne Institute of Technology / R. Bezanson, University of Pittsburgh / A. Pagan, STScI.

There is still much we don’t understand about the period in the early history of the universe known as the Era of Reionization.

It was a time of darkness, without stars or galaxies, and filled with a thick fog of hydrogen gas, until the first stars ionized the surrounding gas and light began to pass through.

Astronomers have spent decades trying to identify sources that emit radiation powerful enough to gradually remove this hydrogen fog that blanketed the early universe.

“Our discovery reveals the important role played by ultrafaint galaxies in the evolution of the early universe,” said astronomer Dr. Irina Chemelinska from the Paris Institute of Astrophysics.

“They produce ionizing photons that convert neutral hydrogen into ionized plasma during the reionization of the universe.”

“This highlights the importance of understanding low-mass galaxies in shaping the history of the universe.”

“These cosmic power plants collectively emit more than enough energy to accomplish their work,” said Dr. Hakim Atek, also of the Paris Institute of Astrophysics.

“Despite their small size, these low-mass galaxies produce large amounts of energetic radiation, and their abundance during this period is so great that their collective impact alters the state of the entire universe can do.”

In the study, astronomers captured and analyzed the spectra of eight very faint galaxies magnified by the lensing star cluster Abel 2744.

They found that these galaxies emit large amounts of ultraviolet light, at levels four times higher than previously thought.

This means that most of the photons that reionized the Universe likely came from these dwarf galaxies.

“With the web, we have stepped into uncharted territory,” said Dr. Themiya Nanayakkara, an astronomer at Swinburne University of Technology.

“Our study reveals more provocative questions that must be answered in efforts to chart the evolutionary history of our beginnings.”

of result It was published in the magazine Nature.

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H. Atek other. 2024. Most of the photons that reionized the universe came from dwarf galaxies. Nature 626, 975-978; doi: 10.1038/s41586-024-07043-6

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VLT spots metallic scar on surface of white dwarf

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A dynamically active planetary system orbits a significant portion of the white dwarf. These stars often exhibit surface metals accreted from a disk of debris. However, the complete journey of a planetesimal from its star-grazing orbit to its final dissolution in its host star is poorly understood. In a new paper, Astrophysics Journal Letter astronomers report the discovery that stars exist that are contaminated with cold metals. WD 0816-310 It cannibalized heavy elements from a planetary body as large as the dwarf planet Vesta.

WD 0816-310 is a magnetic white dwarf star located 63 light-years away in the constellation Papis. Image credit: L. Calçada / ESO.

Dr Stefano Vanullo, an astronomer at the Armagh Observatory and Planetarium, said: 'It is common for some white dwarfs – slowly cooling embers of stars like our Sun – to cannibalize parts of planetary systems. known,” he said.

“Now we find that the star's magnetic field plays a key role in this process, causing scars on the white dwarf's surface.”

The metal signatures the researchers observed on WD 0816-310 are concentrations of metal imprinted on the white dwarf's surface.

Professor Jay Farihi of University College London said: “These metals come from fragments of a planet the size of, or possibly even larger than, Vesta, which at about 500 kilometers in diameter is the second largest asteroid in the solar system. I have proven that.”

To observe WD 0816-310, astronomers FORS2 equipment upon ESO's super large telescope (VLT).

They also relied on archival data from VLT. X shooter instrument This is to confirm the survey results.

The authors noticed that the strength of the metal detections changed as the star rotated, indicating that the metals were concentrated in specific areas on the white dwarf's surface, rather than being spread smoothly across the surface. Suggests.

They also found that these changes were synchronized with changes in the white dwarf's magnetic field, indicating that this metallic scar is located at one of its magnetic poles.

Taken together, these clues indicate that the magnetic field funneled metal into the star, creating the scar.

“Surprisingly, the material was not evenly mixed on the star's surface, as theory predicted. Instead, this scar was a concentrated patch of planetary material that guided falling debris. “We've never seen anything like this before,” said John Landstreet, a professor at Western University.

“ESO offers a unique combination of capabilities needed to observe faint objects like white dwarfs and make sensitive measurements of the star's magnetic field,” Vanullo said.

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Stefano Vanullo other. 2024. Discovery of magnetically induced metal accretion on contaminated white dwarfs. APJL 963, L22; doi: 10.3847/2041-8213/ad2619

Source: www.sci.news

Bizarre White Dwarf Leaves Metallic Marks Following Consumption of Planet

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Artist’s impression of WD 0816-310. Astronomers have discovered scars imprinted on the surface left when a star swallows a planet.

ESO/L. Calzada

Astronomers have discovered a white dwarf star with strange metallic scars on its surface. The scar likely formed when the star tore apart and ate a small planet in its orbit.

Researchers often find white dwarfs with traces of metal in their atmospheres that came from planets that fell into the star. It has long been thought that metals should be evenly distributed across the surfaces of these so-called contaminated white dwarfs; Jay Farihi Researchers at University College London have discovered a strange concentration of metal debris.

Researchers monitored the star, called WD 0816-310, for two months using the Very Large Telescope in Chile. They discovered that the white dwarf had an opaque piece of metal on top of one of its magnetic poles, blocking some of the star’s light as it rotated. This position indicates that material may have been funneled into the star by its magnetic field. “This is the same process that causes auroras on Earth: charged particles follow magnetic fields to the surface,” Farihi said.

The planet that WD 0816-310 destroyed was small, probably about the same size as the solar system’s asteroid Vesta, which is about 525 kilometers in diameter. Its interior is now prominently displayed on its host star, which could make it relatively easy to study what its geochemistry was like before it was engulfed. Such studies may even be one of the best ways to observe small worlds outside our solar system, even after they disappear.

And there may be many other stars that have been similarly damaged. “When we find something outlandish, it’s often because they all looked that way and we just weren’t asking the right questions,” Farihi says. “This is the first, but it probably won’t be the last.” In fact, researchers have already discovered two white dwarfs that appear to have similar scars. If we go back and observe similar stars over and over again, we may discover even more stars.

topic:

Source: www.newscientist.com

Hubble’s Discovery: Dwarf Spiral Galaxy Found in the Coma Constellation

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Astronomers using the NASA/ESA Hubble Space Telescope have captured stunning images of the dwarf spiral galaxy IC 3476 in the constellation of Coma.

This Hubble image shows IC 3476, a dwarf spiral galaxy located 54 million light-years away in the constellation Coma. This image consists of observations made by Hubble's Altitude Survey Camera (ACS) in the near-infrared and optical parts of the spectrum. This is based on data obtained through his two filters. Color is obtained by assigning different hues to each monochromatic image associated with an individual filter. Image credit: NASA / ESA / Hubble / M. Sun.

IC 3476 It is located in the constellation Coma, approximately 54 million light-years from Earth.

This galaxy is first discovered It was proposed by German astronomer Arnold Schwassmann on November 22, 1900.

IC 3476, also known as IRAS 12301+1419 or LEDA 41608, is a member of the Virgo Cluster.

On the other hand, new Hubble images of the galaxy don't look quite as dramatic. The actual physical events occurring in IC 3476 are highly energetic.

“IC 3476 is undergoing a process known as ram pressure stripping, which promotes unusually high levels of star formation within the region of the galaxy itself,” the Hubble astronomers said.

“We tend to associate the letter 'ram' with the acronym RAM, which refers to random access memory in computing.”

“But ram pressure has a perfectly clear definition in physics: it is the pressure exerted on an object by the overall resistance of the fluid as it moves through some form of fluid.”

“If the entire galaxy is under ram pressure, then the galaxy is a 'celestial body', and the intergalactic medium or the intracluster medium (dust and gas that permeates the space between galaxies, in the latter case the intergalactic space) becomes a “celestial body”. fluid'. “

“Lamb pressure stripping occurs when gas is stripped from a galaxy by ram pressure,” the astronomers explained.

“Gas is absolutely key to star formation, so removing this gas could lead to reduced levels of star formation or even a complete cessation.”

“But the ram's pressure could also compress other parts of the galaxy, which could actually promote star formation.”

“This is what appears to be happening in IC 3476: no star formation appears to be occurring at the edges of the galaxy, which are bearing the brunt of the ram pressure separation, but in deeper regions of the galaxy, the rate of star formation slows down. It seems to be clearly above average. ”

Source: www.sci.news

Webb observes auroras on cold brown dwarf star

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Using NASA/ESA/CSA’s James Webb Space Telescope, astronomers detected a brown dwarf with infrared emissions from methane, likely due to energy in the upper atmosphere. The heating of the upper atmosphere that drives this emission is associated with auroras. The brown dwarf, named W1935, is located 47 light-years away.

Artist’s impression of the brown dwarf W1935. Image credit: NASA/ESA/CSA/L. Hustak, STScI.

On Earth, auroras occur when energetic particles blasted into space from the sun are captured by Earth’s magnetic field.

They cascade into the atmosphere along magnetic field lines near the Earth’s poles, colliding with gas molecules and creating eerie, dancing curtains of light.

Jupiter and Saturn have similar auroral processes that involve interaction with the solar wind, but also receive auroral contributions from nearby active moons, such as Io (for Jupiter) and Enceladus (for Saturn). Masu.

“For an isolated brown dwarf like W1935, the absence of a stellar wind that contributes to auroral processes and accounts for the extra energy in the upper atmosphere required for methane emission is puzzling,” American Airlines astronomers said. said Dr. Jackie Faherty. Natural History Museum and colleagues.

Faherty and his colleagues used Webb to observe a sample of 12 cool brown dwarf stars.

These included object W1935, discovered by citizen scientist Dan Caselden who collaborated on the Backyard Worlds Zooniverse project, and object W2220, discovered using NASA’s Wide Field Infrared Survey Explorer.

Webb revealed in great detail that W1935 and W2220 appear to be close clones of each other in composition.

Also, the brightness, temperature, and spectral characteristics of water, ammonia, carbon monoxide, and carbon dioxide were similar.

A notable exception is that W1935 showed emission from methane, in contrast to the expected absorption feature observed for W2220. This was observed at infrared wavelengths, to which Webb is uniquely sensitive.

“We expected methane to be present because it’s everywhere in these brown dwarfs,” Faherty said.

“But instead of absorbing light, we found just the opposite. The methane was glowing. My first thought was, what the hell? Why is this object emitting methane?” Do you want it?

Astronomers used computer models to deduce what might be behind the emission.

Modeling work showed that W2220 has a predictable energy distribution in its atmosphere, becoming colder with increasing altitude.

On the other hand, W1935 produced surprising results. The best models supported a temperature inversion, where the atmosphere becomes warmer as altitude increases.

“This temperature inversion is really puzzling,” says Dr. Ben Burningham, an astronomer at the University of Hertfordshire.

“We’ve seen this kind of phenomenon on planets with nearby stars that can heat the stratosphere, but it’s outrageous to see something like this on a celestial body with no obvious external heat source. .

In search of clues, researchers looked to our backyard: the planets of our solar system.

The gas giant planet could serve as a proxy for what is seen happening 47 light-years away in the atmosphere of 1935 AD.

Scientists have noticed that planets like Jupiter and Saturn have significant temperature inversions.

Research is still ongoing to understand the causes of stratospheric heating, but leading theories about the solar system include external heating by auroras and internal energy transport from deep in the atmosphere, with the former being the leading explanation. ).

According to the research team, W1935 is the first aurora candidate outside the solar system with the signature of methane emission.

It is also the coldest aurora candidate outside the solar system, with an effective temperature of about 200 degrees Celsius (400 degrees Fahrenheit).

In our solar system, the solar wind is the main contributor to the auroral process, and active satellites like Io and Enceladus play the role of planets like Jupiter and Saturn, respectively.

W1935 does not have any companion stars, so stellar winds cannot contribute to this phenomenon. It is not yet known whether an active moon is responsible for her W1935's methane emissions.

“W1935 provides a spectacular expansion of solar system phenomena without any explanatory stellar illumination,” Faherty said.

“With Webb, we can actually ‘lift the lid’ on chemistry and figure out how auroral processes are similar or different outside of our solar system.”

The authors announced that findings this week’s AAS243243rd Meeting of the American Astronomical Society, New Orleans, USA.

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Jacqueline Faherty other. 2024. JWST exhibits the auroral features of frigid brown dwarfs. AAS243Abstract #4359

Source: www.sci.news

Unexpected star formation driven by dwarf galaxies discovered

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A University of Michigan astronomer, Sally Ooi, led a study on the star-forming regions of the host galaxy NGC 2366, a typical dwarf irregular galaxy. This study was credited to the Observatorio de Calar Alto, J. van Eymeren (AIRUB, ATNF), and Á.R. López Sánchez. As it turns out, dwarf galaxies such as NGC 2366 experience a delay in expelling gas, which allows for the star-forming regions to hold onto gas and dust longer, promoting the formation and development of more stars. This delays the onset of strong superwinds by 10 million years, resulting in more active star formation. This discovery was published in the Astrophysical Journal.

This delay offers astronomers a unique opportunity to study a scenario similar to the dawn of the universe, when ultraviolet light begins to ionize hydrogen, changing the universe from opaque to transparent. By observing low-metallicity dwarf galaxies with large amounts of ultraviolet radiation, scientists can gain insight into these early stages of the universe. The use of new technology from the Hubble Space Telescope allows researchers to observe the light of triple ionized carbon in these galaxies. This observational evidence supports the delayed onset of strong superwinds and a greater amount of ultraviolet radiation in these galaxies.

Thanks to these discoveries, scientists may gain a better understanding of the nature of galaxies seen at the dawn of the universe. This information could be important for the upcoming James Webb Space Telescope. The study was published in the Astrophysical Journal and the Astrophysics Journal Letter. The research team involved in these studies included Michelle C. Jecmen, MS Oey, Amit N. Sawant, Ashkviz Danekar, Sergiy Silic, Linda J. Smith, Jens Melinder, Klaus Reiter, Matthew Hayes, Anne E. Jascott, Daniela Calzetti, Yu-Hua Chu, and Bethan L. James. Ultimately, these findings provide valuable insight into the formation and development of stars in low-metallicity dwarf galaxies.

Source: scitechdaily.com

Webb finds small, free-floating brown dwarf in star-forming cluster IC 348

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The newly discovered brown dwarf is estimated to have a mass three to four times that of Jupiter, making it a strong candidate for the lowest mass free-floating brown dwarf ever directly imaged.

This image from Webb’s NIRCam instrument shows the central portion of star cluster IC 348. Image credits: NASA / ESA / CSA / STScI / K. Luhman, Pennsylvania State University / C. Alves de Oliveira, ESA.

Brown dwarfs are cold, dark objects that are between the size of gas giant planets and Sun-like stars.

These objects, also known as failed stars, have star-like properties even though they are too small to sustain hydrogen fusion reactions in their cores.

Typically, their masses are between 11 and 16 Jupiter (the approximate mass that can sustain deuterium fusion) and 75 and 80 Jupiter (the approximate mass that can sustain hydrogen fusion).

“One of the basic questions you’ll find in any astronomy textbook is: What is the smallest star? That’s what we’re trying to answer,” said Kevin, an astronomer at Penn State University.・Dr. Luman said.

The newly discovered brown dwarf resides in IC 348, a star cluster 1,000 light-years away in the constellation Perseus.

The cluster, also known as Collinder 41, Gingrich 1, and Theia 17, contains nearly 400 stars and is about 5 million years old.

IC 348 is part of the larger Perseus star-forming region, and although it is normally invisible to the naked eye, it shines brightly when viewed at infrared wavelengths.

Dr. Luhmann and his colleagues used the following method to image the center of the star cluster. Webb’s NIRCam device Identify brown dwarf candidates based on their brightness and color.

They followed up on the most promising targets using: Webb’s NIRSpec microshutter array.

This process created three interesting targets with masses between three and eight Jupiters and surface temperatures between 830 and 1,500 degrees Celsius.

Computer models suggest that the smallest of these weighs just three to four times as much as Jupiter.

ESA astronomer Dr Catalina Alves de Oliveira said: “With current models, it is very easy to create a giant planet in a disk around a star.”

“But in this cluster, the object is unlikely to form as a disc, but instead as a star, with three Jupiters having a mass 300 times less than the Sun.”

“Then we have to ask how the star formation process takes place at such a very small mass.”

Two of the brown dwarfs identified by the research team exhibit spectral signatures of unidentified hydrocarbons, molecules that contain both hydrogen and carbon atoms.

The same infrared signature was detected in the atmospheres of Saturn and its moon Titan by NASA’s Cassini mission.

It has also been observed in the interstellar medium, the gas between stars.

“This is the first time this molecule has been detected in the atmosphere of an object outside our solar system,” Dr de Oliveira said.

“Models for brown dwarf atmospheres do not predict their existence. We are observing objects that are younger and have lower masses than ever before, and we are seeing something new and unexpected.” .”

a paper Regarding the survey results, astronomy magazine.

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KL Luman other. 2023. JWST survey of planetary mass brown dwarfs in IC 348. A.J. 167, 19; doi: 10.3847/1538-3881/ad00b7

Source: www.sci.news