Latest news with #AlbertoSanna
Yahoo
17-05-2025
- Science
- Yahoo
Star 20 times the Sun's mass caught gorging on gas in cosmic birth ritual
Astronomers have captured a stellar feast in action — the clearest view yet of a massive baby star devouring gas to fuel its rapid growth. The star, dubbed HW2, lies about 2,300 light-years from Earth in a stellar star-forming region known as Cepheus A. Weighing in at 10 to 20 times the mass of our sun, HW2 is a rare example of a massive protostar caught in the act of formation. The discovery also offers new insight into a fundamental astrophysical mystery: how massive stars, which often end their lives in spectacular supernova explosions, manage to gather such enormous amounts of mass during their formation. Using radio observations of ammonia, a molecule common in interstellar space and a common cleaning agent used on earth, astronomers were able to map the swirling disk of gas feeding the star, despite thick clouds of dust cloaking the region, making it obscure. The observations confirm that even the universe's most massive stars grow by pulling in gas from surrounding disks, following the same fundamental process as their smaller stellar siblings. "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, said in a release. "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." In 2019, the team used the Very Large Array radio telescope network in New Mexico to track the radio glow of ammonia molecules, which glow brightly at radio wavelengths. This allowed them to pierce through the dense dust cocoon that blocks visible light to get a look as close as possible to the star. The data show that gas in HW2's accretion disk is plunging inward at a staggering pace, fueling the young star at a rate of about two Jupiter masses per year — one of the fastest stellar growth rates ever recorded. But HW2's future depends heavily on its surroundings, Sanna noted. The team also found an uneven distribution of gas in the disk. According to their observation, the eastern side of the disk holds nearly twice as much material as the western side and displays more turbulence. This imbalance hints that the disk may be receiving an external boost, possibly from a nearby filament-like stream of gas and dust acting as a cosmic pipeline. Such streamers are increasingly believed to connect forming stars with their outer envelopes, channeling fresh material to keep growth going. While these structures around HW2 remain unseen for now, the study lays out predictions that future telescopes can test, Sanna said. "We need to understand for how long HW2 can keep growing," he added. The results of the study will soon be published in the journal Astronomy & Astrophysics. It is available on the arXiv preprint server.
Yahoo
17-05-2025
- Science
- Yahoo
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.
