Latest news with #NationalInstituteforAstrophysics
Yahoo
12-06-2025
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James Webb Space Telescope sees 1st exoplanet raining sand alongside 'sandcastle' partner world
When you buy through links on our articles, Future and its syndication partners may earn a commission. Noted sand-hater Anakin Skywalker may want to cross the planetary system of YSES-1 off his list of potential summer vacation locations. Using the James Webb Space Telescope (JWST), astronomers have discovered a planetary system orbiting a youthful star located 300 light-years away. The system's two planets, YSES-1 b and YSES-1 c, are packed with coarse, rough, and frankly irritating silica material (we get you, Anakin, it does get everywhere). Astronomers say this discovery around a star that is just 16.7 million years old could hint at how the planets and moons of our 4.6 billion-year-old solar system took shape. As both planets are gas giants, they could offer astronomers an opportunity to study the real-time evolution of planets like Jupiter and Saturn. "Observing silicate clouds, which are essentially sand clouds, in the atmospheres of extrasolar planets is important because it helps us better understand how atmospheric processes work and how planets form, a topic that is still under discussion since there is no agreement on the different models," team member Valentina D'Orazi of the National Institute for Astrophysics (INAF) said in a statement. "The discovery of these sand clouds, which remain aloft thanks to a cycle of sublimation and condensation similar to that of water on Earth, reveals complex mechanisms of transport and formation in the atmosphere. "This allows us to improve our models of climate and chemical processes in environments very different from those of the solar system, thus expanding our knowledge of these systems." One of these extrasolar planets, or "exoplanets," YSES-1 c, has a mass around 14 times the mass of Jupiter. On YSES-1 c, this silica matter is located in clouds in its atmosphere, which gives it a reddish hue and creates sandy rains that fall inward towards its core. We guess that the future Darth Vader didn't build too many sandcastles in his youth, but that process is analogous to the formation of sandy matter that YSES-1 b is undergoing. Already possessing a mass around six times that of Jupiter, the still-forming sandcastle planet YSES-1 b is surrounded by a flattened cloud or "circumplanetary disk" that is supplying it with building materials, including silicates. Not only is this the first direct observation of silica clouds (specifically iron-rich pyroxene or a combination of bridgmanite and forsterite) high in the atmosphere of an exoplanet, but it is also the first time silicates have been detected in a circumplanetary disk. The JWST was able to make such detailed direct observations of both planets thanks to the great distances at which they orbit their parent star, which is equivalent to between 5 and 10 times the distance between the sun and its most distant planet, the ice giant Neptune. Though this technique is still restricted to a small number of planets beyond the solar system, this research exemplifies the capability of the JWST to provide high-quality spectral data for exoplanets. This opens the possibility of studying both the atmospheres and circumplanetary environments of exoplanets in far greater detail. Related Stories: — Scientists discover super-Earth exoplanets are more common in the universe than we thought — Does exoplanet K2-18b host alien life or not? Here's why the debate continues — A hidden 'super-Earth' exoplanet is dipping in and out of its habitable zone "By studying these planets, we can better understand how planets form in general, a bit like peering into the past of our solar system," added D'Orazi. "The results support the idea that cloud compositions in young exoplanets and circumplanetary disks play a crucial role in determining atmospheric chemical composition. "Furthermore, this study highlights the need for detailed atmospheric models to interpret the high-quality observational data obtained with telescopes such as JWST." The team's results were published on Tuesday (June 10) in the journal Nature, the same day as they were presented at the 246th meeting of the American Astronomical Society in Anchorage, Alaska.
Yahoo
17-05-2025
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Giant young star is growing by 2 Jupiter masses every year, new study shows
When you buy through links on our articles, Future and its syndication partners may earn a commission. Astronomers have captured the clearest view to date of a massive young star gulping down swirling gas, offering a rare glimpse into how these cosmic titans grow to their enormous sizes. The star in the making, known as HW2, is about 10 to 20 times as massive as our sun and lies about 2,300 light-years from Earth, in the heart of a star-forming region called Cepheus A. Despite the thick shrouds of dust that usually obscure such regions, researchers managed to peer through the veil surrounding HW2 and study the gas feeding its rapid growth. Using radio observations of ammonia, a molecule abundant in interstellar space and familiar on Earth as a common cleaning agent, astronomers mapped the rotating disk of gas and dust swirling around HW2. The results, soon to be published in the journal Astronomy & Astrophysics, confirm that colossal stars that are hundreds of times the mass of our sun grow in the same fundamental way as smaller stars: by gathering gas from swirling gas disks. "We are always trying to get general rules that can explain the largest number of phenomena we observe," study leader Alberto Sanna, a researcher at the National Institute for Astrophysics in Italy, told "Our findings strongly support that the same physical processes, although scaled up, can form both stars like our sun as well as stars of tens of solar masses." The team made their observations in 2019 using the Very Large Array radio telescope network in New Mexico. By tracking the signature of ammonia molecules, which glow brightly at radio wavelengths, the researchers were able to peer through the dense cocoon of dust that obscures visible light and "look as close as possible to the star," said Sanna. The data revealed that gas from HW2's accretion disk is collapsing inward at breakneck speed, feeding the star at an astonishing rate — equivalent to about two Jupiter masses per year, one of the highest stellar growth rates ever recorded. How HW2's evolution unfolds will depend in part on what's happening in its immediate environment, said Sanna. The team's observations show a clear imbalance in the gas distribution within the star's accretion disk: the eastern side contains roughly twice as much gas as the western side and also shows signs of greater turbulence. This asymmetry suggests the disk may be receiving an external injection of material, potentially funneled in by a nearby filament-like stream of gas and dust, according to the new study. Related Stories: — The Very Large Array: 40 years of groundbreaking radio astronomy — Jupiter: A guide to the largest planet in the solar system — Stars: Facts about stellar formation, history and classification This interpretation supports growing evidence that such streamers can connect young stars to their surrounding envelopes, acting as cosmic supply lines and delivering fresh material to the accretion disk to sustain star growth. Sanna and his team cannot yet directly image these streamers that may be feeding HW2, but the new study offers testable predictions that future observations can use to search for them, the researcher said. "We need to understand for how long HW2 can keep growing," he added.
Yahoo
01-04-2025
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Million-mile-long solar whirlwind could help solve sun's greatest mysteries (video)
When you buy through links on our articles, Future and its syndication partners may earn a commission. A twisting, whirling streamer of plasma escaping the sun in the aftermath of a coronal mass ejection (CME) has been captured on video by the European Space Agency's Solar Orbiter, and could provide vital clues about how magnetic energy that drives the solar wind and giant eruptions on the sun is released. The twirling, helical streamer was spotted by Solar Orbiter on Oct. 12, 2022. It lasted for more than three hours, extending up to 2 million kilometers (1.3 million miles) in length, transporting plasma and magnetic energy away from the sun. Solar Orbiter used its Metis instrument, which features a coronagraph to block the glare of the body of the sun, to allow Solar Orbiter to see just the sun's fainter outer atmosphere, called the corona, in both visible and ultraviolet light. It's the wispy corona, filled with streamers, that we can see from Earth during a total solar eclipse. Helical structures have been caught on camera in the solar corona before, but they have never been observed in such detail or for so long. How the streamer developed is now offering solar physicists clues as to what drives the solar wind and CMEs. Related: Earth's sun: Facts about the sun's age, size and history Researchers led by Paolo Romano of the National Institute for Astrophysics at the Astrophysical Observatory of Catania in Italy have studied the twisting streamer and traced it all the way back to its origin in the lower corona. The picture that they present is this: At the base of the corona, magnetic energy becomes stored in taut magnetic field lines. The corona is full of holes, like Swiss cheese, where the magnetic field lines are open — this, they extend out into space rather than bending back onto the sun's surface (called the photosphere) in a closed loop. The solar wind blows through these coronal holes. A phenomenon known as interchange reconnection takes place, which is the magnetic reconnection (where magnetic field lines break and then reconnect, releasing energy) between open and closed magnetic fields in the lower part of the corona. The most powerful reconnection events can liberate enough energy to produce solar flares and exploding magnetic filaments that result in CMEs. On a smaller scale, interchange reconnection powers a constant and global population of jets that inject energy into the corona and through the coronal holes. These jets energize magnetic waves in the solar plasma called Alfvén waves, which in turn push plasma around and through the coronal holes, in the process ejecting matter on the solar wind that blows through those holes. So where does the twisting streamer come into play? Based on observations by Solar Orbiter and its partner in crime, NASA's Parker Solar Probe — which gets so close to the sun as to actually dip into the corona — solar physicists have become convinced that the magnetic structure of escaping plasma from a massive interchange reconnection event is in the form of a "twisted flux rope." A flux rope is a tube of magnetic energy that has erupted in a solar filament, which is a lace or channel of plasma held by closed magnetic fields. Interchange reconnection between the filament and the surrounding open magnetic field lines releases the energy that powers a CME, the resulting ejection being a powerful jet that bursts through the solar corona and into space, dragging plasma with it to form the CME. This flux tube forms the bright center of a CME. And that's exactly what Solar Orbiter witnessed: the twisting flux tube in the aftermath of a powerful interchange reconnection event that released a giant CME into space. Related: Space weather: What is it and how is it predicted? Related Stories: — Solar Orbiter: Seeing the sun like never before — Coronal mass ejections: What are they and how do they form? — NASA's daredevil solar spacecraft survives 2nd close flyby of our sun According to computer simulations, the twisting nature of the flux tube is a natural consequence of a long-duration interchange reconnection. Solar Orbiter's observations with Metis revealed more, however. The inclination, or tilt, of the twisting features in the escaping flux tube decreases with height above the sun, indicating that the magnetic field lines are growing more radially aligned with the sun as they propagate out into the solar system. Perturbations in the magnetic field carried by the streamer might then become amplified as they carry on deep into space. Romano's team speculate that it could be these perturbations that create the magnetic switchbacks, where the direction of the magnetic field in the solar wind suddenly reverses course before continuing onward in a kind of zig-zagging motion, as seen by both Solar Orbiter and Parker Solar Probe. For decades, the sun's greatest mysteries — how the solar corona is heated to more than a million degrees Celsius, for example, and where the energy comes from to drive the solar wind and CMEs — were closely held secrets. Now that Solar Orbiter and Parker Solar Probe are getting as close to the sun as it's about possible to get, at long last the sun is giving up its greatest enigmas. The academic research paper describing Solar Orbiter's observations of the twisting streamer was published March 26 in The Astrophysical Journal.
Yahoo
27-03-2025
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Strange red nova deaths of shrouded stars investigated by 'stellar Sherlocks'
When you buy through links on our articles, Future and its syndication partners may earn a commission. The name "Intermediate Luminosity Red Transients" or "ILRTs" might not be an astronomical term you are familiar with, but these rare, brightness-shifting stars have been quite the mystery in astronomical terms. Now, a team of cosmic detectives, who have dubbed their work "A Study in Scarlett" after the Arthur Conan Doyle novel that first introduced the world to Sherlock Holmes, may have finally cracked the case. The stellar Sherlocks from across the globe suggest that ILRTs are stars that don't just erupt when they reach the end of their lives but experience "truly terminal" and destructive supernova explosions. "Following the discovery of three new ILRTs in 2019, we seized the opportunity to study and better understand these phenomena," team leader and National Institute for Astrophysics (INAF) researcher Giorgio Valerin said in a statement. "We have, therefore, collected data for years through telescopes scattered around the world and even several telescopes in orbit. "We have also resumed the observation campaign of NGC 300 OT, the closest ILRT ever observed, at 'just' six and a half million light-years from us." The ground-based instruments used included La Palma, La Silla, Las Campanas, and Asiago, while data was also collected from space-based telescopes, including the James Webb Space Telescope (JWST), the Neil Gehrels Swift Observatory (SWIFT), and the Spitzer space telescope. ILRTs have been somewhat confusing because their brightness is between that of novas, stellar explosions that stars survive, and "classical" supernovas in which a massive star is destroyed, leaving behind a neutron star or a black hole. The team reached their findings by observing the evolution of four ILRTs. They hoped that this would help them determine whether the star survives these explosions or is completely wiped out. The key to solving this mystery was observing ILRTs like NGC 300 OT over long periods of time. "The first images of NGC 300 OT date back to 2008, and in this work, we have observed it again to study its evolution after more than ten years," Valerin said. "The analysis of the images and spectra collected during these observing campaigns has allowed us to monitor the evolution over time of our targets, obtaining information such as the brightness, temperature, chemical composition, and gas velocities associated with each ILRT we have studied." The Spitzer observations of NGC 300 OT showed this ILRT dimming to a tenth of the brightness of the progenitor star that created this eruption over the course of seven years. Spitzer's images of NGC 300 OT ended when they faded below the detection threshold of this NASA space telescope, which retired in 2020. Just as Holmes made his name investigating many cases, the team had another set of ILRT data to peruse. Analyzing JWST observations of the ILRT AT 2019abn located in the nearby galaxy Messier 51 (M51), they found that this transient is declining in brightness in such a way that it is likely to meet the same fate as NGC 300 OT by becoming fainter than its progenitor star. From this information, the team concluded that ILRTs are explosions that see the total destruction of a star. That is despite the fact that ILRTs appear to be significantly weaker than "classical" core-collapse supernovas. The question is, how do they remain fainter than similar supernova events? The team of cosmic detectives suggests that a defining factor in the make-up of ILTRs could be a dense shroud of gas and dust that surrounds the progenitor stars. This cocoon is heated to temperatures as great as around 10,300 degrees Fahrenheit (5,700 degrees Celsius) over just a few days. The peak in temperature corresponds with a peak in brightness for the ILRT. As this happens, the gas in this stellar shroud accelerates to speeds as great as 1.6 million miles per hour (700 kilometers per second), which is around 1,000 times as fast as the top speed of a Lockheed Martin F-16 jet fighter. "This speed is decidedly lower than that of an exploding supernova, which often reaches 10,000 kilometers per second [22 million mph],' team member and INAF researcher Leonardo Tartaglia said. "Yet, we believe that the star may have really exploded, throwing material at thousands of kilometers per second in every direction, but that this explosion was partially suffocated by the dense blanket of gas and dust around the star, which heats up as a consequence of the violent impact." Thus, the launch of material from around the stellar progenitors of ILRTs can explain how they decrease in brightness over long periods of time. The team termed this phenomenon an "electron capture supernova" a type of stellar explosion that has been long theorized but had not been believed to have been observed. Electron-capture supernovas have been of great interest to astronomers because they seem to mark a boundary between stars of around 10 solar masses and more that explode in supernovas to leave behind black holes and neutron stars, and stars with masses more like the sun that don't "go nova" but fade away as white dwarf stellar remnants. Related Stories: — Dead stars within supernova explosions could solve the dark matter mystery in 10 seconds — Could a supernova ever destroy Earth? — Hubble Telescope sees rare supernova explosion as a violent 'pale blue dot' (image) "We are finally seeing the events that separate stars destined to explode as classical supernovas from stars that will slowly fade away as white dwarfs," Valerin said. Perhaps the team would agree with Holmes' words from The Sign of the Four: "When you have eliminated the impossible, whatever remains, however improbable, must be the truth!"The team's research was published across two papers on March 7 in the journal Astronomy & Astrophysics.
Yahoo
27-02-2025
- Science
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These dwarf galaxies in the Hydra cluster are baffling scientists: 'We found something we didn't expect'
When you buy through links on our articles, Future and its syndication partners may earn a commission. Astronomers have discovered something surprising about the universe's smallest and faintest class of galaxies: Ultra-Diffuse Galaxies (UDGs). A research team studying these galaxies found that around half of the ones they investigated showed signs of motion that defy previous theories about the formation and evolution of such realms. In particular, the team found an unexpected rotational motion of stars within many of these dwarf galaxies. The scientists reached these findings while studying stellar motion in 30 UDGs in the Hydra galaxy cluster located over 160 million light-years away from us. The findings could change our understanding of how UDGs form and evolve. "The results we obtained were doubly satisfying," Chiara Buttitta, a researcher at the National Institute for Astrophysics and co-author of a paper on these results, said in a statement. "Not only were we able to deduce the stellar motions in these extremely faint galaxies, but we found something we didn't expect to observe."The team utilized the "Looking into the faintest With MUSE," or LEWIS, observing program, conducted by the MUSE integral field spectrograph that's installed on the Very Large Telescope (VLT). The VLT is the world's most advanced visible-light astronomical observatory, and is situated in Chile. UDGs were first discovered in 2015; the formation and evolution of these ultrafaint, strangely elongated galaxies immediately presented a puzzle for astronomers. The LEWIS findings allowed the new study's team to determine that UDGs dwell in environments that greatly vary in terms of their physical properties, the amount of dark matter they contain and the motions and compositions of their stars. Specifically, the scientists were able to conduct a detailed investigation of the UDG designated "UDG32." This dwarf galaxy is located at the tail end of a filament of gas attached to the spiral galaxy dubbed "NGC 3314A." One possible theory regarding the formation of UDGs suggests they form when filaments of gas are dragged from larger galaxies via gravitational interactions. If gas clouds remain in these filaments, these clouds can become overly dense and collapse, forming stars that become the foundation of a UDG. The data from LEWIS confirmed that UDG32's association with the filament tail of NGC3314A isn't the result of a coincidental alignment. There's something more that makes UDG32 appear to be situated at the tip of NGC3314A's tidal tail. Additionally, UDG32 is more enriched in elements heavier than hydrogen and helium, which astronomers collectively call "metals," than other UDGs in the Hydra are forged by the nuclear processes occurring at the hearts of stars and are dispersed when these stars explode at the ends of their lives to become the building blocks of the next generation of stars. This is interesting because, despite the stars in UDG32 being younger than the stars in other Hydra cluster UDGs, they are richer in metals. This suggests they formed in the pre-metal-enriched gas and dust shed by a larger and more ancient galaxy, supporting the idea that this UDG was dragged from its spiral galaxy neighbor. Related Stories: — Largest-ever discovery of 'missing link' black holes revealed by dark energy camera (video) — Rare string of 'cosmic pearls' dance together in the universe — Black holes can squash star formation, James Webb Space Telescope finds The team's results are important validation for the LEWIS project, which has thus far doubled the number of UDGs that have been analyzed spectroscopically. Additionally, LEWIS has provided the first "global" view of these faint galaxies within a galaxy cluster that is still forming. "The LEWIS project was a challenge. When this program was accepted by ESO we realized that it was a goldmine of data to be explored. And that is what it turned out to be," Enrichetta Iodice, the LEWIS scientific director, said in the statement. "The 'strength' of LEWIS, thanks to the integral spectroscopy of the instrument used, lies in being able to study simultaneously, for each individual galaxy, not only the motions of the stars, but also the average stellar population," Iodice added, "and, therefore, have indications on the formation age and the properties of globular clusters, fundamental tracers also for the dark matter content. "By putting together the individual results, like in a puzzle, we reconstruct the formation history of these systems." The team's research was detailed across two papers published in the journal Astronomy & Astrophysics.
