Latest news with #Xrays
Malay Mail
a day ago
- General
- Malay Mail
Astronomers discover mysterious star emitting rare combination of X-rays and radio waves
WASHINGTON, May 31 — Astronomers have spotted a star acting unlike any other ever observed as it unleashes a curious combination of radio waves and X-rays, pegging it as an exotic member of a class of celestial objects first identified only three years ago. It is located in the Milky Way galaxy about 15,000 light-years from Earth in the direction of the constellation Scutum, flashing every 44 minutes in both radio waves and X-ray emissions. A light-year is the distance light travels in a year, 5.9 trillion miles (9.5 trillion km). The researchers said it belongs to a class of objects called 'long-period radio transients,' known for bright bursts of radio waves that appear every few minutes to several hours. This is much longer than the rapid pulses in radio waves typically detected from pulsars - a type of speedily rotating neutron star, the dense collapsed core of a massive star after its death. Pulsars appear, as viewed from Earth, to be blinking on and off on timescales of milliseconds to seconds. 'What these objects are and how they generate their unusual signals remain a mystery,' said astronomer Ziteng Wang of Curtin University in Australia, lead author of the study published this week in the journal Nature. In the new study, the researchers used data from Nasa's orbiting Chandra X-ray Observatory, the ASKAP telescope in Australia and other telescopes. While the emission of radio waves from the newly identified object is similar to the approximately 10 other known examples of this class, it is the only one sending out X-rays, according to astrophysicist and study co-author Nanda Rea of the Institute of Space Sciences in Barcelona. The researchers have some hypotheses about the nature of this star. They said it may be a magnetar, a spinning neutron star with an extreme magnetic field, or perhaps a white dwarf, a highly compact stellar ember, with a close and quick orbit around a small companion star in what is called a binary system. 'However, neither of them could explain all observational features we saw,' Wang said. Stars with up to eight times the mass of our sun appear destined to end up as a white dwarf. They eventually burn up all the hydrogen they use as fuel. Gravity then causes them to collapse and blow off their outer layers in a 'red giant' stage, eventually leaving behind a compact core roughly the diameter of Earth — the white dwarf. The observed radio waves potentially could have been generated by the interaction between the white dwarf and the hypothesized companion star, the researchers said. 'The radio brightness of the object varies a lot. We saw no radio emission from the object before November 2023. And in February 2024, we saw it became extremely bright. 'Fewer than 30 objects in the sky have ever reached such brightness in radio waves. Remarkably, at the same time, we also detected X-ray pulses from the object. We can still detect it in radio, but much fainter,' Wang said. Wang said it is thrilling to see a new type of behavior for stars. 'The X-ray detection came from NASA's Chandra space telescope. That part was a lucky break. The telescope was actually pointing at something else, but just happened to catch the source during its 'crazy' bright phase. A coincidence like that is really, really rare - like finding a needle in a haystack,' Wang said. — Reuters
Reuters
2 days ago
- General
- Reuters
Astronomers scrutinize a star behaving unlike any other
WASHINGTON, May 29 (Reuters) - Astronomers have spotted a star acting unlike any other ever observed as it unleashes a curious combination of radio waves and X-rays, pegging it as an exotic member of a class of celestial objects first identified only three years ago. It is located in the Milky Way galaxy about 15,000 light-years from Earth in the direction of the constellation Scutum, flashing every 44 minutes in both radio waves and X-ray emissions. A light-year is the distance light travels in a year, 5.9 trillion miles (9.5 trillion km). The researchers said it belongs to a class of objects called "long-period radio transients," known for bright bursts of radio waves that appear every few minutes to several hours. This is much longer than the rapid pulses in radio waves typically detected from pulsars - a type of speedily rotating neutron star, the dense collapsed core of a massive star after its death. Pulsars appear, as viewed from Earth, to be blinking on and off on timescales of milliseconds to seconds. "What these objects are and how they generate their unusual signals remain a mystery," said astronomer Ziteng Wang of Curtin University in Australia, lead author of the study published this week in the journal Nature, opens new tab. In the new study, the researchers used data from NASA's orbiting Chandra X-ray Observatory, the ASKAP telescope in Australia and other telescopes. While the emission of radio waves from the newly identified object is similar to the approximately 10 other known examples of this class, it is the only one sending out X-rays, according to astrophysicist and study co-author Nanda Rea of the Institute of Space Sciences in Barcelona. The researchers have some hypotheses about the nature of this star. They said it may be a magnetar, a spinning neutron star with an extreme magnetic field, or perhaps a white dwarf, a highly compact stellar ember, with a close and quick orbit around a small companion star in what is called a binary system. "However, neither of them could explain all observational features we saw," Wang said. Stars with up to eight times the mass of our sun appear destined to end up as a white dwarf. They eventually burn up all the hydrogen they use as fuel. Gravity then causes them to collapse and blow off their outer layers in a "red giant" stage, eventually leaving behind a compact core roughly the diameter of Earth - the white dwarf. The observed radio waves potentially could have been generated by the interaction between the white dwarf and the hypothesized companion star, the researchers said. "The radio brightness of the object varies a lot. We saw no radio emission from the object before November 2023. And in February 2024, we saw it became extremely bright. Fewer than 30 objects in the sky have ever reached such brightness in radio waves. Remarkably, at the same time, we also detected X-ray pulses from the object. We can still detect it in radio, but much fainter," Wang said. Wang said it is thrilling to see a new type of behavior for stars. "The X-ray detection came from NASA's Chandra space telescope. That part was a lucky break. The telescope was actually pointing at something else, but just happened to catch the source during its 'crazy' bright phase. A coincidence like that is really, really rare - like finding a needle in a haystack," Wang said.
CNA
2 days ago
- General
- CNA
Astronomers scrutinize a star behaving unlike any other
WASHINGTON :Astronomers have spotted a star acting unlike any other ever observed as it unleashes a curious combination of radio waves and X-rays, pegging it as an exotic member of a class of celestial objects first identified only three years ago. It is located in the Milky Way galaxy about 15,000 light-years from Earth in the direction of the constellation Scutum, flashing every 44 minutes in both radio waves and X-ray emissions. A light-year is the distance light travels in a year, 5.9 trillion miles (9.5 trillion km). The researchers said it belongs to a class of objects called "long-period radio transients," known for bright bursts of radio waves that appear every few minutes to several hours. This is much longer than the rapid pulses in radio waves typically detected from pulsars - a type of speedily rotating neutron star, the dense collapsed core of a massive star after its death. Pulsars appear, as viewed from Earth, to be blinking on and off on timescales of milliseconds to seconds. "What these objects are and how they generate their unusual signals remain a mystery," said astronomer Ziteng Wang of Curtin University in Australia, lead author of the study published this week in the journal Nature. In the new study, the researchers used data from NASA's orbiting Chandra X-ray Observatory, the ASKAP telescope in Australia and other telescopes. While the emission of radio waves from the newly identified object is similar to the approximately 10 other known examples of this class, it is the only one sending out X-rays, according to astrophysicist and study co-author Nanda Rea of the Institute of Space Sciences in Barcelona. The researchers have some hypotheses about the nature of this star. They said it may be a magnetar, a spinning neutron star with an extreme magnetic field, or perhaps a white dwarf, a highly compact stellar ember, with a close and quick orbit around a small companion star in what is called a binary system. "However, neither of them could explain all observational features we saw," Wang said. Stars with up to eight times the mass of our sun appear destined to end up as a white dwarf. They eventually burn up all the hydrogen they use as fuel. Gravity then causes them to collapse and blow off their outer layers in a "red giant" stage, eventually leaving behind a compact core roughly the diameter of Earth - the white dwarf. The observed radio waves potentially could have been generated by the interaction between the white dwarf and the hypothesized companion star, the researchers said. "The radio brightness of the object varies a lot. We saw no radio emission from the object before November 2023. And in February 2024, we saw it became extremely bright. Fewer than 30 objects in the sky have ever reached such brightness in radio waves. Remarkably, at the same time, we also detected X-ray pulses from the object. We can still detect it in radio, but much fainter," Wang said. Wang said it is thrilling to see a new type of behavior for stars. "The X-ray detection came from NASA's Chandra space telescope. That part was a lucky break. The telescope was actually pointing at something else, but just happened to catch the source during its 'crazy' bright phase. A coincidence like that is really, really rare - like finding a needle in a haystack," Wang said.
ABC News
3 days ago
- General
- ABC News
Strange flashing object discovered in deep space puzzles astronomers
In the past few years, astronomers have recorded a handful of very strange radio signals, mostly coming from towards the centre of the Milky Way. Armed with increasingly powerful telescopes, they've detected objects that emit powerful bursts of energy a few times an hour, like a chiming clock — and then fall silent. The source of these "long-period radio transients", or LPTs, hasn't been nailed down, but it was thought they were caused by dead stars. But a newly discovered LPT, reported in the journal Nature, could shift our view about the origin of these mysterious objects. Unlike previous discoveries, this LPT also sends out X-ray pulses, making it the strangest one yet. An international team, led by Curtin University astronomer Ziteng Andy Wang, first detected a radio signal in data captured by the Australian Square Kilometre Array Pathfinder telescope (ASKAP) in Western Australia. Dubbed ASKAP J1832-0911, the object sent out radio waves for two minutes every 44 minutes. By chance the signal was also spotted by NASA's Chandra X-ray Observatory on Valentine's Day last year. Dr Wang said he was "pretty surprised" when he saw pulses of X-rays happening at the same time as the radio waves. "That is a huge discovery," Dr Wang said. The X-ray and radio pulses were emitted for a few weeks, and then fell silent. Had Chandra not been observing that patch of sky, the X-ray bursts would never have been detected. Astronomers have known about flashing objects since the 1960s, but until a few years ago, each one that had been recorded flickered very quickly, switching on and off every few seconds or minutes. Then, in 2022, an Australian-led team discovered an LPT which emitted super-bright radio waves regularly over hours. A handful of other LPTs have been discovered since. Researchers have proposed different theories for the source of these LPTs. One is a super-dense star called a neutron star that spins, regularly hitting Earth with a beam of energy from its poles. But these stars were thought to only be detectable when they were spinning very quickly, becoming too faint to see as they slowed down to LPT-level speeds. Or they could be weaker dead stars — white dwarfs — in binary systems, interacting with other stars. Michael Cowley, an astronomer at Queensland University of Technology who wasn't involved with the new research, pointed out a pre-print study from last year which supported this second theory. "This seemed like a reasonable answer and a promising step toward solving the puzzle," Dr Cowley said. But he said the detection of X-rays coming from ASKAP J1832-0911 "throws a spanner in the works". "Pulsed X-rays are usually associated with rotating neutron stars," Dr Cowley said. He believed this meant that LPTs could be coming from several different sources. "My takeaway is that LPTs don't appear to be a single phenomenon. Instead, they may represent a new category of objects, defined not by a shared origin but by how they behave." Dr Wang said it wasn't clear whether the new observation could be a white dwarf or a neutron star. "Both are possible, but personally I would prefer an isolated neutron star," he said. Whichever it is, the object has an extremely strong magnetic field, several billion times that of the Earth. This makes them very difficult to learn more about, according Stuart Ryder, an astronomer at Macquarie University who also wasn't involved with the research. "They're such extreme states of matter, we don't really have a good understanding of them because we can't replicate that here on Earth," Dr Ryder said. But the sheer weirdness of the object presents other opportunities. As radio telescopes improve, and more LPTs are discovered, they may help physicists understand how matter works in strange environments. "If we can study extra-strong magnetic fields in objects and elsewhere in the Universe, then we can learn a lot about the physics of matter," Dr Ryder said. He believes that understanding this extreme magnetism could help nudge science closer to clean nuclear fusion energy on Earth. "At the end of the day, a star is basically just a natural form of a fusion reactor, and we're trying to replicate those conditions in a very controlled manner here on Earth."
Asharq Al-Awsat
3 days ago
- General
- Asharq Al-Awsat
Astronomers Discover Strange New Celestial Object in Our Milky Way Galaxy
Astronomers have discovered a strange new object in our Milky Way galaxy. An international team reported Wednesday that this celestial object — perhaps a star, pair of stars or something else entirely — is emitting X-rays around the same time it's shooting out radio waves. What's more, the cycle repeats every 44 minutes, at least during periods of extreme activity. Located 15,000 light-years away in a region of the Milky Way brimming with stars, gas and dust, this object could be a highly magnetized dead star like a neutron or white dwarf, Curtin University's Ziteng Andy Wang said in an email from Australia. Or it could be 'something exotic' and unknown, said Wang, lead author of the study published in the journal Nature. NASA's Chandra X-ray Observatory spotted the X-ray emissions by chance last year while focusing on a supernova remnant, or the remains of an exploded star. Wang said it was the first time X-rays had been seen coming from a so-called long-period radio transient, a rare object that cycles through radio signals over tens of minutes. Given the uncertain distance, astronomers can't tell if the weird object is associated with the supernova remnant or not. A single light-year is 5.8 trillion miles. The hyperactive phase of this object, designated ASKAP J1832−091, appeared to last about a month. Outside of that period, the star did not emit any noticeable X-rays. That could mean more of these objects may be out there, scientists said. 'While our discovery doesn't yet solve the mystery of what these objects are and may even deepen it, studying them brings us closer to two possibilities,' Wang said. 'Either we are uncovering something entirely new, or we're seeing a known type of object emitting radio and X-ray waves in a way we've never observed before.' Launched in 1999, Chandra orbits tens of thousands of miles (kilometers) above Earth, observing some of the hottest, high-energy objects in the universe.
