#luminous fast blue optical transient

[mindblowingscience]

A mysterious cosmic explosion created a brilliant flash of light in the space between two galaxies over 3 billion light-years away. The optical flash, which was one of the brightest bursts of blue light in the universe but lasted only a few days, is the latest example of a rare breed of brief astronomical event called a luminous fast blue optical transient (LFBOT). LFBOTs are a complete mystery. The first one to be discovered wasn't observed until 2018. Designated AT2018cow, it was positioned in the spiral arm of its galaxy 200 million light-years away. Nicknamed "the Cow," it was up to 100 times brighter than an ordinary supernova, and was also bright in radio waves, ultraviolet and X-rays. If it was a supernova, it behaved very oddly. Usually, a supernova stays bright for weeks, or even months, and has a recognizable spectrum. Yet the Cow faded after a few days.

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#LFBOT #luminous fast blue optical transient #Space #astronomy #physics #stem #astrophysics

[netmassimo]

An article being published in the journal "Monthly Notices of the Royal Astronomical Society" reports the observation of a Luminous Fast Blue Optical Transient (LFBOT), a rare type of cosmic explosion of still uncertain nature which was cataloged as AT2023fhn. A team of researchers used various telescopes to try to study one of the few phenomena of this type known so far but this brought more questions than answers because its origin was found far from any galaxy.

#astronomy #Luminous Fast Blue Optical Transient #AT2023fhn

[spacetimewithstuartgary]

Astronomers discover signs of life in a star’s explosive death

After a distant star’s explosive death, an active stellar corpse was the likely source of repeated energetic flares observed over several months – a phenomenon astronomers had never seen before, a Cornell-led team reports in new research published Nov. 15 in Nature.

The bright, brief flashes – as short as a few minutes in duration, and as powerful as the original explosion 100 days later – appeared in the aftermath of a rare type of stellar cataclysm that the researchers had set out to find, known as a luminous fast blue optical transient, or LFBOT.

Since their discovery in 2018, astronomers have speculated about what might drive such extreme explosions, which are far brighter than the violent ends massive stars typically experience, but fade in days instead of weeks. The research team believes the previously unknown flare activity, which was studied by 15 telescopes around the world, confirms the engine must be a stellar corpse: a black hole or neutron star.

“We don’t think anything else can make these kinds of flares,” said Anna Y. Q. Ho, assistant professor of astronomy in the College of Arts and Sciences. “This settles years of debate about what powers this type of explosion, and reveals an unusually direct method of studying the activity of stellar corpses.”

Ho is the first author of “Minutes-duration Optical Flares with Supernova Luminosities,” published with more than 70 co-authors who helped characterize the LFBOT officially labeled AT2022tsd and nicknamed “the Tasmanian devil,” and the ensuing pulses of light seen roughly a billion light years from Earth.

Ho wrote the software that flagged the event in September 2022, while sifting through a half-million changes, or transients, detected daily in an all-sky survey conducted by the Califrnia-based Zwicky Transient Facility.

Then in December 2022, while routinely monitoring the fading explosion, Ho and collaborators Daniel Perley of Liverpool John Moores University in England, and Ping Chen of the Weizmann Institute of Science in Israel, met to review new observations conducted and analyzed by Ping – a set of five images, each spanning several minutes. The first showed nothing, as expected, but the second picked up light, followed by an intensely bright spike in the middle frame that quickly vanished.

“No one really knew what to say,” Ho recalled. “We had never seen anything like that before – something so fast, and the brightness as strong as the original explosion months later – in any supernova or FBOT. We’d never seen that, period, in astronomy.”

To further investigate the abrupt rebrightening, the researchers engaged partners who contributed observations from more than a dozen other telescopes, including one equipped with a high-speed camera. The team combed through earlier data and worked to rule out other possible light sources. Their analysis ultimately confirmed at least 14 irregular light pulses over a 120-day period, likely only a fraction of the total number, Ho said.

“Amazingly, instead of fading steadily as one would expect, the source briefly brightened again – and again, and again,” she said. “LFBOTs are already a kind of weird, exotic event, so this was even weirder.”

Exactly what processes were at work – perhaps a black hole funneling jets of stellar material outward at close to the speed of light – continues to be studied. Ho hopes the research advances longstanding goals to map how stars’ properties in life may predict the way they’ll die, and the type of corpse they produce.

In the case of LFBOTs, rapid rotation or a strong magnetic field likely are key components of their launching mechanisms, Ho said. It’s also possible that they aren’t conventional supernovas at all, instead triggered by a star’s merger with a black hole.

“We might be seeing a completely different channel for cosmic cataclysms,” she said.

The unusual explosions promise to provide new insight into stellar lifecycles typically only seen in snapshots of different stages – star, explosion, remnants – and not as part of a single system, Ho said. LFBOTs may present an opportunity to observe a star in the act of transitioning to its afterlife.

“Because the corpse is not just sitting there, it’s active and doing things that we can detect,” Ho said. “We think these flares could be coming from one of these newly formed corpses, which gives us a way to study their properties when they’ve just been formed.”

#science #space #astronomy #physics #news #astrophysics

[michaelgabrill]

NASAs Hubble Finds Bizarre Explosion in Unexpected Place

A very rare, strange burst of extraordinarily bright light in the universe just got even stranger – thanks to the eagle-eye of NASA’s Hubble Space Telescope. The phenomenon, called a Luminous Fast Blue Optical Transient (LFBOT), flashed onto the scene where it wasn’t expected to be found, far away from any host galaxy. Only Hubble […] from NASA https://ift.tt/jQUzCVX

#NASA #space #NASA’s Hubble Finds Bizarre Explosion in Unexpected Place #Michael Gabrill

[eurovisionsocialnewswire]

SPACE: NASA’s Hubble Space Telescope discovers strange explosion in 'unexpected place' [PHOTO]

NASA has observed what was described as a very unusual and rare burst of extraordinarily bright light in the universe, the U.S. space agency said on Thursday, October 5. The scientists said with the help of the Hubble Space Telescope they managed to record the phenomenon called a Luminous Fast Blue Optical Transient (LFBOT), an intense burst that shines intensely in blue light and evolves…

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[reasoningdaily]

Futurism: Dead Star Springs Back to Life

"We'd never seen that, period, in astronomy."

Team Edward

These are the undead cosmic flares of a killer, Bella.

As Space.com reports, scientists at Cornell University have detected renewed signs of life in a deceased star — a striking, never-before-seen discovery offering researchers an illuminating glimpse into the exotic netherworld of star births and deaths.

The far-off star in question, located roughly a billion lightyears from Earth in a distant galaxy and affectionately nicknamed "the Tasmanian Devil," was already considered rare due to the nature of its initial death. When it died, it triggered something called a "luminous fast blue optical transient," or LFBOT — a massive, superpowerful cataclysm that gave off an intense blue glow. But while LFBOTs shine brighter than more common supernovas, as Space.com notes, they're known to fade faster, flaming out within just days.

Until now, that is. According to the Cornell astronomers' research, which was published yesterday in the journal Nature, the Tasmanian Devil LFBOT is still radiating intermittent flashes of blue light, as powerful and radiant as the star's original cataclysmic flares — a fascinating glimmer of activity from a stellar corpse.

"We had never seen anything like that before  —  something so fast, and the brightness as strong as the original explosion months later  —  in any supernova or FBOT," Anna Ho, an assistant professor of astronomy at the university, said in a statement. "We'd never seen that, period, in astronomy."

Tasmanian Devil

Per a university press release, Ho first spotted the Tasmanian Devil a little over a year ago in September 2022 while sieving through data from the Zwicky Transient Facility. The researcher and her team kept an eye on the rare celestial event as it faded, and were taken aback to notice, weeks later, that the presumed dead star was continuing to emit sporadic, minutes-long flares.

Using observations from over a dozen different telescopes, the team continued to monitor the celestial site, ultimately concluding that the maybe-not-so-dead star emitted 14 separate, powerful LFBOT-like flares over the course of 120 days.

"Amazingly, instead of fading steadily as one would expect, the source briefly brightened again — and again, and again," said Ho. "LFBOTs are already a kind of weird, exotic event, so this was even weirder."

Even in death, it seems, stars might just be more alive than we think.

The "corpse is not just sitting there," said Ho, "it's active and doing things that we can detect."

More on stars: Scientists Puzzled by Stars That Disappeared from the Sky

#Dead Star Springs Back to Life

[spacenutspod]

In September 2022, an automated sky survey detected what seemed to be a supernova explosion about one billion light-years away. The Zwicky Transient Facility (ZTF) spotted it and gave it the name AT2022tsd. But something was different about this supernova. Supernovae explode and shine brightly for months, while AT2022tsd exploded brightly and then faded within days. That’s when astronomers realized it wasn’t a regular supernova at all. It was a luminous fast blue optical transient (LFBOT), a relatively new class of object that was only discovered a few years earlier and remains mysterious. Then something even stranger happened. AT2022tsd, given the nickname ‘Tasmanian Devil,’ brightened again and again. This was both a surprise and a puzzle, two things that always attract the attention of astronomers. After its initial detection, follow-up observations in X-rays showed that the Tasmanian Devil was the brightest LFBOT ever detected. Not only that, but it rivalled the brightest gamma-ray bursts ever detected. These facts, along with the object’s repeated brightening, made it one of the strangest transients ever detected. A team of researchers led by Cornell Assistant Professor of Astronomy Anna Ho gathered all the data they could to determine what was behind the Tasmanian Devil’s unusual behaviour. Their results are in a new paper titled “Minutes-duration optical flares with supernova luminosities.” The paper was published in the journal Nature. “This settles years of debate about what powers this type of explosion and reveals an unusually direct method of studying the activity of stellar corpses.”Anna Ho, Cornell University “In recent years, certain luminous extragalactic optical transients have been observed to last only a few days,” the authors write in their paper. “Their short observed duration implies a different powering mechanism from the most common luminous extragalactic transients (supernovae), whose timescale is weeks.” “Here we report observations of minutes-duration optical flares in the aftermath of an AT2018cow-like transient, AT2022tsd.” AT 2018cow was a powerful explosion up to 100 times brighter than a supernova. It’s one of the few reported FBOTs. This image shows The Cow approximately 80 days after the explosion from the W.M. Keck Observatory in Maunakea, Hawaii. The Cow is nestled in the CGCG 137-068 galaxy, 200 million light years from Earth. Image Credit: Raffaella Margutti/Northwestern University The Tasmanian Devil’s repeated flashes were as short as a few minutes long. They were also as powerful as the initial explosion 100 days prior. These repeated flashes only deepened the mystery around LFBOTs. 15 telescopes around the world watched the flashes, and the research team combed through the observations to try to determine what type of object was behind this remarkable behaviour. In December, Ho was routinely monitoring the fading initial explosion and captured five new images of the object that each spanned a few minutes. The first image showed nothing, but the middle image showed an intense brightening that quickly vanished. Then nothing again. Ho shared the images with collaborators, and they were speechless. “We think these flares could be coming from one of these newly formed corpses,”Anna Ho, Cornell University “No one really knew what to say,” Ho recalled. “We had never seen anything like that before – something so fast, and the brightness as strong as the original explosion months later – in any supernova or FBOT. We’d never seen that, period, in astronomy.” The Thai National Telescope captured this flare from AT2022tsd. This flare was nearly as bright as the initial burst detected with the Zwicky Transient Facility. Time on the x-axis is in minutes. Image Credit: Ho et al. 2023. The team’s analysis showed 14 separate spikes in brightness over a 120-day period. According to Ho, that’s likely only a fraction of the total number. “Amazingly, instead of fading steadily as one would expect, the source briefly brightened again – and again, and again,” she said. “LFBOTs are already a kind of weird, exotic event, so this was even weirder.” There are some events and objects out there in the cosmos that flash repeatedly, and the researchers worked to either confirm or eliminate them. The Devil wasn’t a supernova, but could it have been a tidal disruption event (TDE) where a black hole feeds on material and flares brightly? Does its light and frequency match any other type of astronomical transient? This figure from the research shows how the light from AT2022tsd compares to other bright transient objects. TDEs, shown in purple circles, are well outside the parameter space of the Tasmanian Devil. Other objects in the figure are Long Gamma-Ray Bursts (LGRBs) and their cousins, Long-Duration, Low-Luminosity Gamma-Ray Bursts. The figure also shows LFBOTs and CC SNs, which are Core-Collapse Supernovae. The signals from AT2022tsd don’t match those from gamma-ray bursts, tidal disruption events, or supernovae. Image Credit: Ho et al. 2023. The team detected a single optical and multiple x-ray flares from the Tasmanian Devil. But the optical flare didn’t coincide with any of the x-ray flares. Also, there was no detectable periodicity to any of the flaring. The fact that the team couldn’t find any optical flaring in the research into other LFBOTs was also confounding. “To our knowledge, this phenomenon—minute-timescale optical flares at supernova-like luminosities, with order-of-magnitude amplitude variations, persisting for 100+ days—has no precedent in the literature,” the researchers write in their paper. For now, AT2022tsd is still a mystery. It could be a supergiant star collapsing as a supernova and then forming an accretion ring. It could be a black hole funnelling jets of material into space. Or it could be another LFBOT, but we could be seeing it from a strange angle. If we are, that could explain the Tasmanian Devil’s X-rays. “The lack of detected flares in other LFBOTs could be because of the viewing angle: AT2018cow is thought to have been observed close to the plane of the circumburst ‘disk’ rather than face-on, and a more on-axis viewing angle for AT2022tsd could also help explain the substantially more luminous X-ray emission,” the authors explain in their research. Artist’s concept of one of the brightest explosions ever seen in space: a Luminous Fast Blue Optical Transient (LFBOT). Credit: NASA The researchers came to a conclusion, but it’s an incomplete one. The Tasmanian Devil must be a dead star, either a black hole or a neutron star. “We don’t think anything else can make these kinds of flares,” said Anna Y.Q. Ho, assistant professor of astronomy in the College of Arts and Sciences. “This settles years of debate about what powers this type of explosion and reveals an unusually direct method of studying the activity of stellar corpses.” If the Tasmanian Devil is a type of dead star, it’s not behaving like the others. “We might be seeing a completely different channel for cosmic cataclysms,” Ho said. Something unprecedented may be going on with the Devil. As a dead star, the light coming from it could signal its transition into a sort of stellar afterlife. It could be a new type of stellar corpse. “Because the corpse is not just sitting there, it’s active and doing things that we can detect,” Ho said. “We think these flares could be coming from one of these newly formed corpses, which gives us a way to study their properties when they’ve just been formed.” The post Can a Dead Star Keep Exploding? appeared first on Universe Today.

#space #astronomy #news #science

[topreviewin]

The Hubble area Telescope recently noticed one thing unusual: an extremely bright, very quickly flash of light that popped up in the center of no place. Officially called a Luminous Quick Blue Optical Transient (LFBOT), the strange benefit of this unusual occasion ended up being it took place outside a galaxy. These flashes have now been seen just a few times given that they had been found in 2018, which certain occasion ended up being called The Finch. Hubble ended up being always keep track of the flash’s source point, that was between two galaxies: 50,000 light-years far from a more substantial spiral galaxy and around 15,000 light-years far from a smaller sized galaxy. It's astronomers puzzled, as they activities had been considered to issue from interior galaxies in which performers tend to be creating — but this occasion occurred a long way away from any star-forming area. This is an artist’s idea of one of several brightest explosions previously observed in area. Known as a Luminous Quick Blue Optical Transient (LFBOT), it shines extremely in blue light and evolves quickly, achieving top brightness and diminishing once more in just a few times, unlike supernovae which simply take months or months to dim. Just a few past LFBOTs have now been found since 2018. And all take place inside galaxies in which performers are increasingly being produced. But because example reveals, the LFBOT flash found in 2023 by Hubble ended up being seen between galaxies. This just compounds the secret of just what these transient activities tend to be. Because astronomers don’t understand the main procedure behind LFBOTs, the surge shown let me reveal purely conjecture based on some understood transient sensation. NASA, ESA, NSF's NOIRLab, M. Garlick , M. Zamani “The Hubble observations were really the crucial thing. They made us realize that this was unusual compared to the other ones like that, because without the Hubble data we would not have known,” stated lead specialist Ashley Chrimes in a statement. The flash has also been seen making use of various other devices such as the ground-based Gemini Southern observatory, which unearthed that the heat associated with Finch ended up being an unbelievable 20,000 levels Celsius (around 36,000 Fahrenheit). These flashes brighten and dim in a few days, versus various other brief astronomical activities like supernovas which have a tendency to enhance and dim during a period of months. Boffins believed that LFBOTs could be developed by a specific and unusual types of supernova that takes place to huge and temporary performers. As they performers don’t continue for very long, they have a tendency found near stellar nurseries in which they have been produced. But this brand-new flash difficulties that idea. “The more we learn about LFBOTs, the more they surprise us,” stated Chrimes. “We’ve now shown that LFBOTs can occur a long way from the center of the nearest galaxy, and the location of the Finch is not what we expect for any kind of supernova.” It could possibly be the flashes aren't indeed brought on by supernovas but they are alternatively brought on by performers becoming torn aside by black colored holes. Or maybe a fast-moving celebrity ended up being moving amongst the two galaxies and exploded during its trip. While the activities are incredibly unusual, it is challenging inform at this time of study. “The discovery poses many more questions than it answers,” stated Chrimes. “More work is needed to figure out which of the many possible explanations is the right one.” Editors' guidelines #Hubble #observes #mysterious #bright #explosion #labeled as #Finch #Digital #styles

[spacetodaypt]

Hubble Sees a Mysterious Flash in Between Galaxies

While the night sky may appear tranquil (and incredibly beautiful), the cosmos is filled with constant stellar explosions and collisions. Among the rarest of these transient events are what is known as Luminous Fast Blue Optical (LFBOTs), which shine intensely bright in blue light and fade after a few days. These transient events are only detectable by telescopes that continually monitor the sky.…

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[inkyvoids]

Last April, the Zwicky Transient Facility in California was scanning the sky, when it picked up a fleeting astronomical phenomenon — an event that burst into view and then disappeared within a relatively short timeframe. Most such transients are supernovae, though others can occur, too. Owing to transients’ short shelf lives, astronomers wasted no time in following up on the finding. The initial discovery triggered a prepared sequence of observations; within weeks, they were measuring the event’s visible spectrum with the Gemini South telescope in Chile, its radio waves with the Very Large Array in New Mexico, and its X-rays with the Chandra telescope in space. By May, the Hubble Space Telescope was trained on the target, too. Out of that data, a team in the Netherlands, the UK, Denmark, and South Africa pieced together a picture of the event, posted on the arXiv astronomy preprint server. It turned out to be a member of a rare subclass of transients known as luminous fast blue optical transients (luminous FBOTs). Officially designated AT2023fhn, it was dubbed “the Finch,” continuing the trend of nicknaming FBOTs after animals. (Others include “the Koala,” “the Camel,” and “the Cow.”) Luminous FBOTs are intensely bright — up to 100 times brighter than typical supernovae — and, like other FBOTs, maintain a persistent blue color throughout the entirety of their evolution. Even among transients, FBOTs are unusually short-lived, rising rapidly to high peak luminosities before dimming in a matter of days. Unlike other transients, their precise nature remains a mystery.

#optical transient #hubble space telescope #sky and telescope

[gaetaniu]

Hubble trova una bizzarra esplosione in un luogo inaspettato

Questo è un concetto artistico di una delle esplosioni più luminose mai viste nello spazio. Chiamato Luminous Fast Blue Optical Transient (LFBOT), brilla intensamente nella luce blu e si evolve rapidamente, raggiungendo il picco di luminosità e spegnendosi di nuovo nel giro di pochi giorni, a differenza delle supernove che impiegano settimane o mesi per attenuarsi. Dal 2018 sono stati scoperti…

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[astroimages]

Hubble detecta um tipo de explosão rara no universo chamada de Luminous Fast Blue Optical Transients (LFBOTs), além de ser rara, essa explosão detectada pelo Hubble ocorreu no espaço entre duas galáxias!!! É o universo cheio de seus mistérios!!!

LEIA AGORA NO BLOG!!!

Hubble Detecta Uma Rara e Violenta Explosão no Universo - https://spacetoday.com.br/hubble-detecta-uma-rara-e-violenta-explosao-no-universo/

[tracygrenier-blog]

NYTimes: A Cow, a Camel and a Finch Exploded in Space. What Is Going On?

A Cow, a Camel and a Finch Exploded in Space. What Is Going On? https://www.nytimes.com/2023/07/19/science/explosions-black-holes-lfbots.html?smid=nytcore-android-share

[spacetimewithstuartgary]

Astronomers witness energetic switch on of black hole Royal Astronomical

A team of astronomers led by researchers from the University of Birmingham, University College London and Queen’s University Belfast have discovered one of the most dramatic 'switches on' of a black hole ever seen.

They will present their findings today, Tuesday 4 July, at the 2023 National Astronomy Meeting in Cardiff.

The work will also be published in Monthly Notices of the Royal Astronomical Society.J221951-484240, known as J221951, is one of the most luminous transients - astrophysical objects that change their brightness over a short period of time - ever recorded.

It was discovered by Dr Samantha Oates, an astronomer at the University of Birmingham, and her team, in September 2019 while searching for the electromagnetic light from a gravitational wave event.

The team were using the Ultra-Violet and Optical Telescope on board the Neil Gehrels Swift Observatory to look for a kilonova, the sign of a neutron star merging with another neutron star or a black hole.

A kilonova typically appears blue, then fades and turns more red in colour over a timescale of days. What they found instead something even more unusual: J221951.

The transient appeared blue, but didn’t change colour or fade rapidly as a kilonova would.

Multiple telescopes were used to follow-up J221951 and determine its nature, including NASA’s Swift/UVOT and Hubble Space Telescope, the South African Large Telescope, and ESO facilities such as the Very Large Telescope and the GROND instrument on the MPG/ESO 2.2-metre telescope at the La Silla Observatory.

A spectrum of J221951 taken with the Hubble Space Telescope ruled out the association of J221951 with the gravitational wave event. By examining the light spectrum of J221951, Dr Oates and her team were able to determine that the source is around 10 billion light years away, in contrast to the gravitational wave signal which was detected less than 0.5 billion light years away.

The fact that it shines so brightly at such a large distance makes J221951 one of the most luminous transients ever detected. 

Evidence suggests that J221951 came into existence as a result of a supermassive black hole feeding on surrounding material very rapidly.

A red galaxy was observed at the location of J221951 prior to its detection, and the location of J221951 is consistent with the galaxy’s centre, where a massive black hole would naturally reside.

It started to shine very suddenly – around 10 months prior to initial detection - meaning the black hole started feeding very quickly after being quiet for some time.

The ultraviolet spectrum shows absorption features consistent with material pushed outwards by a huge release of energy.

This, combined with its large luminosity, makes this one of the most dramatic 'switches on' of a black hole ever seen. 

The team have identified two possible mechanisms that could explain this extreme feeding of a super massive black hole.

The first is that it may have been caused by a tidal disruption event - the disruption of a star as it passes close to the supermassive black hole at the centre of its galaxy.

The second is that it may have been produced by an active galactic nucleus ‘changing state’ from dormant to active.

J221951 would then be the signal that a dormant black hole at the centre of the host galaxy has begun to feed on material from an accretion disk.Dr Matt Nicholl, a member of the team from Queen’s University Belfast, said, “Our understanding of the different things that supermassive black holes can do has greatly expanded in recent years, with discoveries of stars being torn apart and accreting black holes with hugely variable luminosities.”

He adds, “J221951 is one of the most extreme examples yet of a black hole taking us by surprise.

Continued monitoring of J221951 to work out the total energy release might allow us to work out whether this is a tidal disruption of a star by a fast-spinning black hole, or a new kind of AGN switch on”.Dr N. Paul Kuin, another member of the team from the Mullard Space Science Laboratory at University College London, said, “The key discovery was when the ultraviolet spectrum from Hubble ruled out a Galactic origin.

This shows how important it is to maintain a space-based UV spectrograph capability for the future.”Dr Samantha Oates adds, "In the future we will be able to obtain important clues that help distinguish between the tidal disruption event and active galactic nuclei scenarios.

For instance, if J221951 is associated with an AGN turning on we may expect it to stop fading and to increase again in brightness, while if J221951 is a tidal disruption event we would expect it to continue to fade.

We will need to continue to monitor J221951 over the next few months to years to capture its late-time behaviour."

image....This illustration depicts a star (in the foreground) experiencing spaghettification as its sucked in by a supermassive black hole (in the background) during a ‘tidal disruption event’. In a new study, done with the help of ESO’s Very Large Telescope and ESO’s New Technology Telescope, a team of astronomers found that when a black hole devours a star, it can launch a powerful blast of material outwards.  Credit: ESO/M. Kornmesser

#science #space #astronomy #physics #news #spacetimewithstuartgary #starstuff #spacetime #black hole

[antonio-velardo]

Antonio Velardo shares: A Cow, a Camel and a Finch Exploded in Space. What Is Going On? by Jonathan O’Callaghan

By Jonathan O’Callaghan Astronomers have yet to determine the cause of luminous fast blue optical transients, and the latest they have detected is raising even more questions. Published: July 19, 2023 at 09:28AM from NYT Science https://ift.tt/aEkLXeT via IFTTT

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#antonio velardo #IFTTT #NYT

[arxt1]

MUSSES2020J: The Earliest Discovery of a Fast Blue Ultra-luminous Transient at Redshift 1.063. (arXiv:2205.14889v1 [astro-ph.HE])

In this letter we report a discovery of an ultra-luminous fast evolving transient in rest-frame UV wavelengths, MUSSES2020J, soon after its occurrence by using the Hyper Suprime-Cam (HSC) mounted on the 8.2m Subaru telescope. The rise time of about 5 days with an extremely high UV peak luminosity share similarities with a handful of fast blue optical transients whose peak luminosities are comparable with the most luminous supernovae while their timescales are significantly shorter (hereafter "fast blue ultra-luminous transient," FBUT). In addition, MUSSES2020J is located near the center of a normal low-mass galaxy at redshift of 1.063, suggesting a possible connection between the energy source of MUSSES2020J and the central part of the host galaxy. Possible physical mechanisms of powering this extreme transient such as a wind-driven tidal disruption event and an interaction between supernova and circumstellar material are qualitatively discussed based on the first multiband early-phase light curve of FBUTs, while whether the scenarios can quantitatively explain the early photometric behavior of MUSSES2020J requires systematical theoretical investigations. Thanks to the ultra-high luminosity in UV and blue optical wavelengths of these extreme transients, a promising number of FBUTs from local to high-z universe can be discovered through deep wide-field optical surveys in the near future.

from astro-ph.HE updates on arXiv.org https://ift.tt/49JMwC3