Latest news with #FRBs
CNN
14-03-2025
- Science
- CNN
A radio burst was pulsing from the Milky Way. Astronomers traced it to a dead star
Over the past decade, scientists have detected a puzzling phenomenon: radio pulses coming from within our Milky Way galaxy that would pulse every two hours, like a cosmic heartbeat. The long radio blasts, which lasted between 30 and 90 seconds, appeared to come from the direction of the Ursa Major constellation, where the Big Dipper is located. Now, astronomers have zeroed in on the surprising origin of the unusual radio pulses: a dead star, called a white dwarf, that is closely orbiting a small, cool red dwarf star. Red dwarfs are the most common type of star in the cosmos. The two stars, known collectively as ILTJ1101, are orbiting each other so closely that their magnetic fields interact, emitting what's known as a long period radio transient, or an LPT. Previously, long radio bursts were only traced to neutron stars, the dense remnants left after a colossal stellar explosion. But the discovery, described in a study published Wednesday in the journal Nature Astronomy, shows the movements of stars within a stellar pair can also create rare LPTs. 'We have for the first time established which stars produce the radio pulses in a mysterious new class of 'long period radio transients,'' said lead study author Dr. Iris de Ruiter, a postdoctoral scholar at the University of Sydney in Australia. The unprecedented observations of such bright, long radio bursts from this binary star system are just the beginning, astronomers say. The discovery could help scientists better understand what types of stars are capable of producing and sending radio pulses across the cosmos — and in this case, reveal the history and dynamics of two entwined stars. Locked in a stellar dance To solve the Milky Way mystery, de Ruiter devised a method to identify radio pulses lasting seconds to minutes within the archives of the Low-Frequency Array telescope, or LOFAR, a network of radio telescopes throughout Europe. It's the largest radio array that operates at the lowest frequences detectable from Earth. De Ruiter, who developed her method while she was a doctoral student at the University of Amsterdam, uncovered a single pulse from observations made in 2015. Then, focusing on the same patch of sky, she found six more pulses. All of them appeared to originate from a faint red dwarf star. But de Ruiter didn't think the star would be able to produce radio waves by itself. Something else had to be instigating it. The pulses differed from fast radio bursts, which are incredibly bright, millisecond-long flashes of radio waves. Almost all FRBs originate from outside our galaxy, and while some of them repeat, many appear to be one-off events, de Ruiter said. Fast radio bursts are also much more luminous. 'The radio pulses are very similar to FRBs, but they each have different lengths,' said study coauthor Charles Kilpatrick, research assistant professor at Northwestern University's Center for Interdisciplinary Exploration and Research in Astrophysics, in a statement. 'The pulses have much lower energies than FRBs and usually last for several seconds, as opposed to FRBs which last milliseconds. There's still a major question of whether there's a continuum of objects between long-period radio transients and FRBs, or if they are distinct populations.' De Ruiter and her colleagues conducted follow-up observations of the red dwarf star using the 21-foot (6.5-meter) Multiple Mirror Telescope at the MMT Observatory on Mount Hopkins in Arizona, as well as the LRS2 instrument on the Hobby-Eberly Telescope, located at the McDonald Observatory in the Davis Mountains in Texas. The observations showed the red dwarf was moving back and forth rapidly, and its motion matched the two-hour period between radio pulses, Kilpatrick said. The back-and-forth motion was due to another star's gravity tugging on the red dwarf. The researchers were able to measure the motions and calculate the mass of the companion star, which they determined to be a white dwarf. The team found that the two stars, located 1,600 light-years from Earth, were pulsing together as they orbited a common center of gravity, completing one orbit every 125.5 minutes. Deciphering mysterious pulses The research team believes there are two possible causes behind the pulses. Either the white dwarf has a strong magnetic field that routinely releases the pulses, or the magnetic fields of the red dwarf star and the white dwarf interact as they orbit. The team has planned to observe ILTJ1101 and study any ultraviolet light that may be emanating from the system, which could reveal more about how the two stars have interacted in the past. De Ruiter also hopes the team can observe the system in radio light and X-rays during a pulse event, which could shed light on the interaction between the magnetic fields. 'At the moment the radio pulses have disappeared completely, but these might turn back on again at a later time,' de Ruiter said. The team is also combing through LOFAR data in search of other long pulses. 'We are starting to find a few of these LPTs in our radio data,' said study coauthor Dr. Kaustubh Rajwade, a radio astronomer in the department of physics at the University of Oxford, in a statement. 'Each discovery is telling us something new about the extreme astrophysical objects that can create the radio emission we see.' Other research groups have found 10 long radio pulse-emitting systems over the past couple of years, and they are trying to determine what creates them because the pulses, all of which originate in the Milky Way, 'are unlike anything we knew before,' de Ruiter said. Unlike the short bursts produced by pulsars, or rapidly spinning neutron stars, LPTs can last anywhere from a few seconds to nearly an hour, said Natasha Hurley-Walker, radio astronomer and associate professor at the Curtin University node of the International Centre for Radio Astronomy Research in Australia. Hurley-Walker was not involved in the new study. 'Looking back, transient radio sources have stimulated some of the most exciting discoveries in astrophysics: the discovery of pulsars and therefore neutron stars, the discovery of FRBs which have unlocked the capacity to measure the otherwise invisible matter between galaxies, and now the discovery of LPTs, where we're only at the tip of the iceberg in terms of what they will tell us,' Hurley-Walker said via email. 'What's fascinating to me is that now that we know these sources exist, we're actually finding them in historical data going back decades — they were hiding in plain sight.' Scanning the sky with powerful radio telescopes will only lead to more incredible findings, she said. 'The biggest would most likely be the discovery of technosignatures via SETI,' Hurley-Walker said of signals that could be created by intelligent life, which is something the SETI Institute has sought out for decades.
Yahoo
14-03-2025
- Science
- Yahoo
Astronomers crack the case of a mysterious deep space radio signal that repeats every 2 hours
When you buy through links on our articles, Future and its syndication partners may earn a commission. Astronomers have cracked the case of a mysterious repeating radio signal that has been a mystery since it was uncovered last year. The team tracked the signal back to a strange binary system containing a dead star or "white dwarf" and a red dwarf stellar companion. The radio pulse repeats every 2 hours and was first detected a decade ago. It came from the direction of the Big Dipper. This new research indicates that the cause of this repeating radio signal is the magnetic fields of the white dwarf and its red dwarf stellar companion slamming together in this tight binary, designated ILTJ1101. Previously, long-period radio bursts like this one had only been traced back to neutron stars, meaning this work puts an entirely new spin on their origins."There are several highly magnetized neutron stars, or magnetars, that are known to exhibit radio pulses with a period of a few seconds," team member and Northwestern astrophysicist Charles Kilpatrick said in a statement. "Some astrophysicists also have argued that sources might emit pulses at regular time intervals because they are spinning, so we only see the radio emission when the source is rotated toward us. "Now, we know at least some long-period radio transients come from binaries. We hope this motivates radio astronomers to localize new classes of sources that might arise from neutron star or magnetar binaries." The team's research was published in the journal Nature Astronomy on Wednesday (March 12). Team leader Iris de Ruiter from the University of Sydney in Australia first discovered the signal in 2024 when she was searching through archival data collected by the Low Frequency Array (LOFAR). LOFAR is the largest radio telescope operating at the lowest frequencies that can be detected from pulse first appeared in LOFAR data in 2015, and after finding its first instance, de Ruiter found six more pulses from the same source. These flashes of radio waves can last anywhere from several seconds to a few minutes. Despite the difference in duration, the pulses repeat regularly, once every two hours. The pulses have some similarities with a cosmic phenomenon called "fast radio bursts" or FRBs," but are much rarer. "The radio pulses are very similar to FRBs, but they each have different lengths," Kilpatrick said. "The pulses have much lower energies than FRBs and usually last for several seconds, as opposed to FRBs, which last milliseconds. "There's still a major question of whether there's a continuum of objects between long-period radio transients and FRBs, or if they are distinct populations." The team wanted to know what the source of these regular radio pulses is, so they performed follow-up investigations with the Multiple Mirror Telescope (MMT) Observatory in Arizona and the McDonald Observatory in Texas. This revealed the origin of the pulses was two stars located around 1,600 light-years from Earth that are pulsing in unison. The two stars whip around each other once every 125.5 minutes. The researchers then further investigated the system for a full two-hour-long cycle using MMT discovering the true nature of this system. The team's detailed observations allowed them to track the system's movement in detail while gaining information from the red dwarf star by breaking its light down into different wavelengths or spectra. "The spectroscopic lines in these data allowed us to determine that the red dwarf is moving back and forth very rapidly with exactly the same two-hour period as the radio pulses," Kilpatrick said. "That is convincing evidence that the red dwarf is in a binary system." This back-and-forth rocking of this star seems to be the result of a barely visible companion in ILTJ1101 gravitationally tugging on it. The variation of the motion revealed to the team the mass of this very faint companion. This allowed them to determine it is a white dwarf, a stellar remnant that is created when a star with around the mass of the sun reaches the end of its life and its collapses while its outer layers are shrugged off. "In almost every scenario, its mass and the fact that it is too faint to see means it must be a white dwarf," Kilpatrick explained. "This confirms the leading hypothesis for the white dwarf binary origin and is the first direct evidence we have for the progenitor systems of long-period radio transients." Related Stories: — Astronomers discover record haul of 25 new repeating 'fast radio bursts' — Record-breaking radio burst could help us find the universe's missing matter — Shortest 'fast radio bursts' ever discovered last only 1 millionth of a second Astronomers are now planning to study the high-energy ultraviolet emissions of ILTJ1101. This could reveal the temperature of the white dwarf and additional details of red dwarf/white dwarf binaries like this one. "It was especially cool to add new pieces to the puzzle,' team leader de Ruiter said. "We worked with experts from all kinds of astronomical disciplines. "With different techniques and observations, we got a little closer to the solution step by step.'
Yahoo
03-03-2025
- Science
- Yahoo
Fast Radio Burst Traced Back to The Last Place We Expected
The mystery of fast radio bursts (FRBs) just got a little bit weirder. A team of astronomers has just traced a burst called FRB 20190208A back to the distant galaxy that spat it out – and they found a tiny, faint dwarf galaxy that seems to be more than halfway across the observable Universe. That's a really unusual place to find one of these mysterious signals, and it confirms they are way more complex than we currently understand. "The majority of fast radio burst host galaxies seem to be massive, star-forming galaxies – perhaps implying that most FRBs are produced by magnetars formed from core collapse supernovae," astronomer Danté Hewitt of the University of Amsterdam told ScienceAlert. "However, the faintness of the FRB 20190208A host galaxy implies that it's one of the least massive FRB host galaxies we've ever seen – so that was definitely surprising!" Fast radio bursts are an intriguing cosmic conundrum. They are huge spikes of radio waves that appear in radio telescope observations, lasting just milliseconds, but discharging in that time as much energy as 500 million Suns. Most of them flare just once, randomly, making them impossible to predict, and very difficult to trace back to a source. Some, however, are repeat offenders, continuing to spit out signals, sometimes randomly, sometimes in a timed pattern. These are usually a bit easier to trace, because astronomers can watch for them and study them more closely. We don't currently have a good grasp on what makes them. There's a growing body of evidence that erupting magnetars are the culprit for at least some of them; but the different ways FRBs can present indicates that we don't have the whole story. Looking at where they come from is one way to fill in some of the gaps. This brings us to FRB 20190208A, a repeating burst first detected in February 2019. Hewitt and his colleagues used radio telescopes to observe the location of the burst for a total of 65.6 hours. In that time, between February 2021 and August 2023, they caught the source bursting twice more. This information allowed them to pinpoint its location in the sky. They then used optical telescopes to take deep sky observations to see what sort of galaxy might be lurking there. "Our initial attempts at identifying a host galaxy revealed no source at the FRB position. We were a little baffled," Hewitt said. "There are a few possible explanations in such a case, but seemingly 'hostless' FRBs are quite rare (since most FRB sources appear to be in massive galaxies). But then, when we saw the images from the Gran Telescopio Canarias, there was a very exciting 'Oh wow! Look! There's actually a faint smudge right where the bursts are coming from' moment." Dwarf galaxies are difficult to see, which is only exacerbated by distance. Because this one is so faint, the researchers were unable to derive a confident distance measurement; but, by looking at the way the radio light of the FRB dispersed as it traveled through space, it could be a light travel time of some 7 billion years. That would make FRB 20190208A one of the most distant FRBs ever detected, which is very nifty. But it's the identity of the tiny galaxy that really sparks the imagination. "This host galaxy is most likely 10-100 times fainter than the vast majority of other FRB host galaxies, perhaps on par with the Magellanic Clouds," Hewitt said. "Naturally, dwarf galaxies such as these do not house a lot of the stars in the Universe. So finding an FRB in such a galaxy may indicate that there are environmental conditions (e.g. the metallicity: whether the gas is pure hydrogen or not) that are conducive to the production of (some) FRB sources." So far, only a small number of FRBs have been localized. What's interesting is that more repeating FRBs have been traced to dwarf galaxies than non-repeating FRBs. This could be an observation bias; but it could alternatively mean that the conditions in dwarf galaxies are somehow more conducive to the production of repeating FRBs. Dwarf galaxies, Hewitt explained, are known to host some of the most massive stars in the Universe due to their low metallicity. When these stars die, they don't go quietly, blowing up the sky in core-collapse supernovae. Those collapsed cores then go on to become highly magnetized neutron stars, or magnetars. "Finding repeating FRB sources in dwarf galaxies thus potentially links these repeating FRB sources with massive star progenitors," Hewitt said. "It's a little poetic. When the most massive stars die, they unleash some of the most energetic explosions in the Universe; and then maybe, the remnants of those explosions continue to scream into the void, repeatedly producing FRBs." We're not quite yet at the point where we can solve this fascinating puzzle. But we're getting closer. It's discoveries like these that take us, step by painstaking step, towards a full understanding of what is behind these wild, huge explosions in the sky. "It's also a little bit of a cautionary tale for the future," Hewitt told ScienceAlert. "The story of FRB 20190208A tells us that in order to robustly associate an FRB with a host galaxy, we will sometimes need both a very precise position from radio arrays, as well as very deep imaging using the largest optical telescopes we currently have at our disposal. That is simply not something that can be done yet for thousands of sources." The team's research has been published in The Astrophysical Journal Letters. Blue Ghost Makes History With Perfect Moon Landing: Amazing Photos This Star Goes Nova Every 80 Years. Here's Where to Look For It in 2025. Blue Ghost Captures Stunning Moon Footage Ahead of Historic Landing
Yahoo
25-02-2025
- Science
- Yahoo
Mysterious fast radio burst traced back to massive 'cosmic graveyard' of ancient stars
When you buy through links on our articles, Future and its syndication partners may earn a commission. Astronomers have been forced to reassess the origins of mysterious, rapid radio wave blasts called "fast radio bursts" (FRBs). This rethink was brought about by an FRB first detected last year, which has been traced back to the "cosmic graveyard" of a massive "dead" galaxy filled with ancient stars located 2 billion light-years from Earth. FRBs are usually attributed to the supernova deaths of massive young stars in younger galaxies experiencing bouts of star formation. This event also triggers the birth of highly magnetic neutron stars, or "magnetars." However, this FRB source galaxy appears to lack such elements, meaning FRB-producing events may be more diverse than previously thought. "This new FRB shows us that just when you think you understand an astrophysical phenomenon, the universe turns around and surprises us," team member and Northwestern University scientist Wen-fai Fong said. "This 'dialogue' with the universe is what makes our field of time-domain astronomy so incredibly thrilling.' This theory-altering research began in Feb. 2024 when the Canadian Hydrogen Intensity Mapping Experiment (CHIME) detected a new FRB, which was later designated FRB 20240209A. Most FRBs flare once, lasting mere milliseconds and emitting more energy than the sun radiates in a year. However, FRB 20240209A flared repeatedly, with the same source generating 21 pulses between February and July 2024. Six of these pulses were detected by a smaller version of CHIME, an "outrigger" telescope located around 37.3 miles (60 kilometers) from the main instrument. These outriggers exist to allow astronomers to pinpoint the source of the FRBs CHIME detects. Thus, the team was able to do this backtracking exercise for FRB 20240209A. With the source of FRB 20240209A located, the team performed follow-up observations with the W.M. Keck and Gemini observatories to learn as much as they could about its environment. If the scientists were expecting a young galaxy like the typical FRB source, they were in for a surprise. Their follow-up investigation showed FRB 20240209A originated from the edge of an 11.3-billion-year-old team set about learning more about this galaxy by performing advanced computer simulations. This revealed that the galactic host of this FRB is extremely luminous and has a mass of around 100 billion times the mass of our sun. "It seems to be the most massive FRB host galaxy to date," team member and Northwestern Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) scientist Tarraneh Eftekhari said. "It's among some of the most massive galaxies out there." The source of this FRB within the galaxy also presents a conundrum. That is because FRBs usually originate well within their galaxies. FRB 20240209A, however, came from the outskirts of its host galaxy, around 130,000 lightyears from the galactic center. "Among the FRB population, this FRB is located the furthest from the center of its host galaxy," said Vishwangi Shah, a graduate student at McGill, who led the effort to pinpoint the source of FRB 20240209A. "This is both surprising and exciting, as FRBs are expected to originate inside galaxies, often in star-forming regions. "The location of this FRB so far outside its host galaxy raises questions as to how such energetic events can occur in regions where no new stars are forming." Prior to this, only one FRB had ever been traced to the outer limits of a galaxy. In 2022, FRB 20200120E was traced to a dense star cluster, or globular cluster, on the outskirts of Messier 81 (M81), a spiral galaxy around 12 million light-years from Earth in the constellation Ursa emerging from very different galaxies, FRB 20240209A and FRB 20200120E shared many similarities. "A few years ago, the M81 FRB was surprisingly discovered within a dense cluster of stars called a globular cluster," Fong said. "That event single-handedly halted the conventional train of thought and made us explore other progenitor scenarios for FRBs."Since FRB 20200120E was detected, no FRB had like it had been observed. That led Fong and the team to believe FRB 20200120E was a one-off discovery — until now."In fact, this CHIME FRB could be a twin of the M81 event. It is far from its home galaxy, far away from where any stars are being born, and the population of stars in its home galaxy is extremely old. It's had its heyday and is now coasting into retirement," Fong said. "At the same time, this type of old environment is making us rethink our standard FRB progenitor models and turning to more exotic formation channels, which is exciting." Thus far, around 100 FRBs have been linked to a galactic host, and most of these have been connected to a magnetar — a highly magnetic form of neutron all neutron stars, magnetars are formed when massive stars run out of their fuel for nuclear fusion. This means the outward flow of energy that supports them against collapse is cut off, and the star can no longer support itself against the crushing inward force of its own gravity. As the star's core rapidly crushes down to form a neutron star, the outer layers and most of the star's mass are blown away in a core-collapse supernova. "The prevailing theory is that FRBs come from magnetars formed through core-collapse supernovae," Eftekhari said. "That doesn't appear to be the case here. While young, massive stars end their lives as core-collapse supernovae, we don't see any evidence of young stars in this galaxy. "Thanks to this new discovery, a picture is emerging that shows not all FRBs come from young stars. Maybe there is a subpopulation of FRBs that are associated with older systems."The researchers believe that just like FRB 20200120E, FRB 20240209A may have come from a globular cluster. This is significant because globular clusters are associated with other powerful events associated with older stars, including the collisions and mergers of two neutron stars or a white dwarf collapsing under its own gravity. Events that could also give rise to FRBs."A globular cluster origin for this repeating FRB is the most likely scenario to explain why this FRB is located outside its host galaxy," Shah said. "We do not know for a fact if there is a globular cluster present at the FRB position and have submitted a proposal to use the James Webb Space Telescope for follow-up observations of the FRB location. If yes, it would make this FRB only the second FRB known to reside in a globular cluster. "If not, we would have to consider alternative exotic scenarios for the FRB's origin.' Related Stories: — Astronomers have pinpointed the origin of mysterious repeating radio bursts from space — Where do fast radio bursts come from? Astronomers tie mysterious eruptions to massive galaxies — Mysterious fast radio bursts could be caused by asteroids slamming into dead stars "It's clear that there's still a lot of exciting discovery space when it comes to FRBs and that their environments could hold the key to unlocking their secrets," Eftekhari concluded. The team's research was detailed at the end of January in two papers published in The Astrophysical Journal Letters.
Yahoo
08-02-2025
- Science
- Yahoo
New fast radio burst detector could sift through 'a whole beach of sand' to solve big cosmic mystery
When you buy through links on our articles, Future and its syndication partners may earn a commission. Researchers have successfully tested a new technology that detects fast radio bursts in the night sky faster than ever before, uncovering a treasure trove of data to help astronomers investigate the source of these mysterious space phenomena. Developed by astronomers and engineers at Australia's national science agency, the Commonwealth Scientific and Industrial Research Organization (CSIRO), the new system — known as the Commensal Realtime ASKAP Fast Transient Coherent, or CRACO — was designed to rapidly detect fast radio bursts (FRBs) and other transient phenomena using CSIRO's ASKAP radio telescope in Western Australia. FRBs are sporadic, intense flashes of radio wave energy that can be brighter than entire galaxies. In just thousandths of a second, an FRB can emit as much energy as the sun does over three days, typically at a radio frequency of about 1,400 hertz. Given their unpredictable nature as well as how fast they can come and go, gathering data on FRBs can be difficult, making them one of astronomy's more exciting mysteries. This data gap is what a team, led by Andy Wang from Curtin University's node of the International Center for Radio Astronomy Research (ICRAR), set out to solve. Remarkably, in the system's first test, Wang found more objects than he'd anticipated, including two FRBs, a couple of sporadically emitting standard neutron stars, and better data for four known pulsars. The latter helped refine the locations of these pulsars, which are spinning neutron stars. Since that first test, additional searches have found more than 20 FRBs. "We were focused on finding fast radio bursts, a mysterious phenomenon that has opened up a new field of research in astronomy," Dr. Wang said in an ICRAR statement. "CRACO is enabling us to find these bursts better than ever before. We have been searching for bursts 100 times per second and in the future we expect this will increase to 1,000 times per second." Keith Bannister, a CSIRO astronomer and engineer who led the team that built CRACO, likened its capabilities to "sifting through a whole beach of sand to look for a single five-cent coin every minute." The system processes about 100 billion pixels per second, scanning ASKAP's "live" view of the sky in search of fleeting cosmic signals. Located at Inyarrimanha Ilgari Bundara, the CSIRO Murchison Radio-astronomy Observatory on Wajarri Yamaji Country, the ASKAP radio telescope is already a major radio astronomy facility for international scientists, so CRACO's integration into ASKAP is expected to broaden the observatory's scientific impact worldwide. Related Stories: — Astronomers have pinpointed the origin of mysterious repeating radio bursts from space — Where do fast radio bursts come from? Astronomers tie mysterious eruptions to massive galaxies — Mysterious fast radio bursts could be caused by asteroids slamming into dead stars "Once at full capacity, CRACO will be a game changer for international astronomy," Wang said. "We're also detecting long-period transients, which remain mysterious objects within our galaxy. Both fast radio bursts and these transients were first discovered in Australia, so it is great that we're continuing the path of discovery with this impressive technology." As part of CSIRO's Australia Telescope National Facility, CRACO will soon be available to astronomers around the globe, enabling rapid identification of transient celestial signals and paving the way for further discoveries in the cosmos. The first batch of findings was published this week in Publications of the Astronomical Society of Australia.
