Latest news with #Near-InfraredSpectrograph
Yahoo
11-04-2025
- Science
- Yahoo
NASA's autopsy of planet swallowed by a star gives astronomers a surprise
When many stars reach billions of years in age and run out of fuel, they become dying stars known as red giants. The stars expand and can engulf nearby planets, effectively incinerating them. In approximately five billion years, Earth's own sun will turn into a red giant and engulf planets, including our blue marble. While astronomers have identified many of these red giant stars, it was only recently that the process of eating a planet had been directly observed. Astronomers have identified many red giant stars and suspected that in some cases they consume nearby planets, but the phenomenon had never been directly observed before. In 2023, scientists discovered a star nearing the end of its life had swelled and absorbed a planet that is likely about the size of Jupiter. Now, with additional observations from the James Webb Space Telescope, they say there's been a 'surprising twist.' Instead of eating the planet, Webb's observations show the planet's orbit shrank over millions of years, pulling the celestial body closer to its demise until it was fully engulfed. 'Because this is such a novel event, we didn't quite know what to expect when we decided to point this telescope in its direction,' Ryan Lau, an astronomer at the National Science Foundation National Optical-Infrared Astronomy Research Laboratory in Tucson, Arizona, said in a statement. 'With its high-resolution look in the infrared, we are learning valuable insights about the final fates of planetary systems, possibly including our own.' Lau is the lead author of a new paper published Thursday in The Astrophysical Journal. Using the telescope's Mid-Infrared Instrument and Near-Infrared Spectrograph, the researchers examined the Milky Way galaxy scene about 12,000 light-years away from Earth. While the sun had been recognized as more like our sun, a measurement from the Mid-Infrared Instrument found the star was not as bright as it should have been if it had evolved into a red giant. The finding indicated to researchers that there was no swelling to engulf the planet, as once believed. 'The planet eventually started to graze the star's atmosphere. Then it was a runaway process of falling in faster from that moment,' team member Morgan MacLeod of the Harvard-Smithsonian Center for Astrophysics and the Massachusetts Institute of Technology, explained. 'The planet, as it's falling in, started to sort of smear around the star.' The planet would have blasted gas away from the outer layers of the star. The Near-Infrared Spectrograph revealed a hot disk of molecular gas surrounding the star, where carbon monoxide was detected. 'With such a transformative telescope like Webb, it was hard for me to have any expectations of what we'd find in the immediate surroundings of the star,' said Vassar College's Colette Salyk, an exoplanet researcher and a co-author of the new paper. 'I will say, I could not have expected seeing what has the characteristics of a planet-forming region, even though planets are not forming here, in the aftermath of an engulfment.'
The Independent
11-04-2025
- Science
- The Independent
NASA's autopsy of planet swallowed by a star gives astronomers a surprise
When many stars reach billions of years in age and run out of fuel, they become dying stars known as red giants. The stars expand and can engulf nearby planets, effectively incinerating them. In approximately five billion years, Earth's own sun will turn into a red giant and engulf planets, including our blue marble. While astronomers have identified many of these red giant stars, it was only recently that the process of eating a planet had been directly observed. Astronomers have identified many red giant stars and suspected that in some cases they consume nearby planets, but the phenomenon had never been directly observed before. In 2023, scientists discovered a star nearing the end of its life had swelled and absorbed a planet that is likely about the size of Jupiter. Now, with additional observations from the James Webb Space Telescope, they say there's been a 'surprising twist.' Instead of eating the planet, Webb's observations show the planet's orbit shrank over millions of years, pulling the celestial body closer to its demise until it was fully engulfed. 'Because this is such a novel event, we didn't quite know what to expect when we decided to point this telescope in its direction,' Ryan Lau, an astronomer at the National Science Foundation National Optical-Infrared Astronomy Research Laboratory in Tucson, Arizona, said in a statement. 'With its high-resolution look in the infrared, we are learning valuable insights about the final fates of planetary systems, possibly including our own.' Lau is the lead author of a new paper published Thursday in The Astrophysical Journal. Using the telescope's Mid-Infrared Instrument and Near-Infrared Spectrograph, the researchers examined the Milky Way galaxy scene about 12,000 light-years away from Earth. While the sun had been recognized as more like our sun, a measurement from the Mid-Infrared Instrument found the star was not as bright as it should have been if it had evolved into a red giant. The finding indicated to researchers that there was no swelling to engulf the planet, as once believed. 'The planet eventually started to graze the star's atmosphere. Then it was a runaway process of falling in faster from that moment,' team member Morgan MacLeod of the Harvard-Smithsonian Center for Astrophysics and the Massachusetts Institute of Technology, explained. 'The planet, as it's falling in, started to sort of smear around the star.' The planet would have blasted gas away from the outer layers of the star. The Near-Infrared Spectrograph revealed a hot disk of molecular gas surrounding the star, where carbon monoxide was detected. 'With such a transformative telescope like Webb, it was hard for me to have any expectations of what we'd find in the immediate surroundings of the star,' said Vassar College's Colette Salyk, an exoplanet researcher and a co-author of the new paper. 'I will say, I could not have expected seeing what has the characteristics of a planet-forming region, even though planets are not forming here, in the aftermath of an engulfment.'
Yahoo
04-04-2025
- Science
- Yahoo
JWST finds spiral galaxy about 5 times more massive than Milky Way — scientists call it 'Big Wheel'
When you buy through links on our articles, Future and its syndication partners may earn a commission. A team of astronomers at the University of Milano-Bicocca has uncovered a colossal spiral galaxy that existed just 2 billion years after the Big Bang, which gave birth to the universe some 13.8 billion years ago. Nicknamed "Big Wheel," it is in fact one of the largest galaxies ever observed from this early cosmic era. The scientists found Big Wheel near a quasar, which is a powerful and active supermassive black hole, using the James Webb Space Telescope (JWST). The galaxy lies 11.7 billion light-years away from our corner of the cosmos, and its given nickname comes from its remarkably fast rotation and huge size. It's five times more massive than the Milky Way, for context, stretches across 100,000 light-years. More specifically, the astronomers used new spectroscopic observations with the JWST's Near-Infrared Spectrograph (NIRSpec) to confirm that Big Wheel is a rotating disk. The galaxy's rotation curve, an important characteristic of spiral galaxies, shows a pattern typical of flat rotation curves seen in mature galaxies. The velocity of the galaxy's rotation increases as you move outward from the center, reaching a maximum rotational velocity of several hundred miles per second, which is also similar to much more developed galaxies. Big Wheel's rotational velocity also aligns with the local Tully-Fisher relationship, a correlation between the size and rotation speed of galaxies observed today. What this all means it that, despite its youth, the galaxy behaves in a manner consistent with some of the largest, most mature spiral galaxies we see in the present universe. Big Wheel exists during a time when most galaxies are expected to be small and in their earliest stages of development. Yet, it's fully formed. "This galaxy is spectacular for being among the largest spiral galaxies ever found, which is unprecedented for this early era of the universe," Charles Steidel, the study's lead author and an astronomy professor at Caltech, in a statement. So, how could this happen? One potential clue lies in Big Wheel's environment. The galaxy resides in a dense region of space where galaxy number densities are more than ten times higher than the cosmic average. This dense environment could provide the perfect conditions for rapid galaxy growth. Sebastiano Cantalupo, co-author of the study, suggests Big Wheel may have benefited from efficient gas accretion, which carried the coherent angular momentum necessary for the formation of large disks. Additionally, the frequent mergers of gas-rich galaxies in this crowded region may have contributed to its massive size and rapid growth. "We think this may open the door to understanding how some galaxies were able to bypass the usual slow process of star formation and grow to enormous sizes in the early universe," Cantalupo said in the statement. The discovery suggests that galaxy formation might not be as slow or gradual as previously thought, especially in environments rich in gas and merging galaxies. Related Stories: — Scientists used JWST instruments 'wrong' on purpose to capture direct images of exoplanets — This astronomer found a sneaky extra star in James Webb Space Telescope data — James Webb Space Telescope investigates the origins of 'failed stars' in the Flame Nebula Big Wheel challenges current cosmological models. Its size and mass far exceed predictions for galaxies at similar redshifts, making it an outlier in the galaxy population. Down the line, astronomers may need to adjust their models to account for the possibility of rapid galaxy growth under such dense conditions. The study was published on March 17 in the journal Nature Astronomy.
New York Times
26-03-2025
- Science
- New York Times
Auroras Are Spotted on Neptune for the First Time, and Lead to a New Mystery
The vermilion, amethyst and jade ribbons of the northern and southern lights are some of Earth's most distinctive features. But our planet doesn't have a monopoly on auroras. Scientists have spied them throughout the solar system, weaving through the skies of Mars, Saturn, Jupiter and even on some of Jupiter's fiery and icy moons. Lights glow in the skies of Uranus, too. But auroras around our sun's most distant planet, Neptune, have long eluded astronomers. That has changed with the powerful infrared instruments aboard the James Webb Space Telescope. In a study published on Wednesday in the journal Nature Astronomy, scientists reveal unique auroras that spill over either side of Neptune's equator, a contrast with the glowing gossamer seen arcing over other worlds' poles. Astronomers are thrilled to see the completion of an aurora-hunting quest decades in the making. 'Everyone is very excited to prove that it's there, just like we thought,' said Rosie Johnson, a space physics researcher at Aberystwyth University in Wales who wasn't involved with the new study. This discovery will also allow scientists to study aspects of Neptune that have previously been out of reach. 'They're using aurora to understand the shape of the planet's magnetic field, which is seeing the unseen,' said Carl Schmidt, a planetary astronomer at Boston University who wasn't involved with the new study. Each world generates auroras differently, but the basics are the same. Energetic particles (often from the sun, but sometimes from a moon's volcanic eruptions) slam into an atmosphere and bounce off gases. That particle collision briefly causes flashes of light. And if a world has a magnetic field, that guides the location of the auroras. Auroras don't always glow in visible light; Saturn, for example, emits mostly ultraviolet auroras. But they can be observed with the right telescopes. It hasn't been possible until now to spot Neptune's atmospheric lights. 'Astronomers have been trying to detect the aurora of Neptune for decades, and each attempt has failed,' said Henrik Melin, a planetary scientist at Northumbria University in England and one of the study's authors. Voyager 2, the only spacecraft to fly by Neptune (in 1989), found hints of an aurora. But all follow-up observations — even with the Hubble Space Telescope — failed to spy telltale shimmering. Fortunately, the Webb telescope, launched in 2021, has come to the rescue. Heidi Hammel, an astronomer at the Association of Universities for Research in Astronomy and another of the study's authors, has been studying Neptune since the 1980s. She thought that if Webb 'was powerful enough to see the earliest galaxies in the universe, it'd better be powerful enough to see things like aurorae on Neptune,' she said. 'And by golly, it was.' Using the telescope's Near-Infrared Spectrograph, astronomers caught Neptune's infrared auroras in June 2023. And unlike Earth's, they dance not above the poles, but its mid-latitudes. That's because Neptune has a wonky magnetic field that is tilted by 47 degrees from the planet's spin axis. The new Webb observations also reveal why Neptune's auroras have been invisible until now. Nearly 40 years ago, Voyager 2 recorded a temperature of around 900 degrees Fahrenheit for Neptune's upper atmosphere. But the Webb telescope shows that the temperature has dropped, to close to 200 degrees. That lower temperature means the auroras are dimmer. In fact, Neptune's aurora is glowing 'with less than 1 percent of the brightness we expected, explaining why we haven't seen it,' said James O'Donoghue, a planetary astronomer at the University of Reading in England and one of the study's authors. 'However, that means we now have a new mystery on our hands: How has Neptune cooled down so much?' With the detection of Neptune's strange light show, answers may be forthcoming. 'Auroras are like a TV screen,' said Leigh Fletcher, a planetary scientist at the University of Leicester in England and one of the study's authors. They are 'allowing us to watch the delicate dance of processes in the magnetosphere — all without actually being there.'
