The European Space Agency's (ESA) Euclid space telescope has spotted 31 previously unknown quasars dating to the universe's earliest chapter, including the two oldest ever found.
The discoveries, described July 6 in the journal Astronomy & Astrophysics, more than double the number of known quasars from that primordial era and could help astronomers unravel one of cosmology's biggest mysteries: how supermassive black holes grew so enormous so quickly after the Big Bang.
"It's a big step towards understanding these fascinating objects on a more fundamental level," Antonio La Marca, an ESA research fellow on the Euclid team, said in a statement.
Quasars are among the brightest objects in the universe. They form when gas and dust spiral into a galaxy's central supermassive black hole, heating up and releasing enormous amounts of energy that can outshine the galaxy itself. Each of the two most ancient quasars detected in the new study shone with the light of a trillion suns, according to the researchers.
Euclid spotted the quasars while surveying the distant universe. Twelve of them have redshifts of 7 or higher, meaning their light has traveled for more than 13 billion years and dates to the universe's first 770 million years. Two of the objects, with redshifts of 7.77 and 7.69, are the most ancient quasars ever identified, shining just 670 million years after the Big Bang, when the universe was only about 5% of its current age.
"These early quasars date back to the Universe's infancy," Daming Yang, an astronomer at Leiden University in the Netherlands and first author of the new study, said in the statement. "By finding and studying them, we can better understand how these enormous systems formed and grew so quickly — one of the greatest mysteries in astrophysics."
Finding quasars from the early universe has long been difficult because they are rare and incredibly distant. Until now, astronomers had identified only the brightest examples, making it difficult to understand the broader population during this early era. Euclid's wide-field survey is changing that by detecting fainter quasars across huge swaths of the sky.
The latest discoveries represent only a fraction of what the telescope is expected to find during its six-year mission, which will cover more than one-third of the total sky once complete. Mounted with a pair of instruments that see in visible and near-infrared light, Euclid is currently assembling the largest-ever 3D map of the universe. Scientists expect the survey to uncover hundreds of similarly ancient quasars, providing an unprecedented look at how the universe's earliest galaxies and supermassive black holes evolved.
Euclid has also taken some time to study the nearby universe, revealing more than 60 million individual stars packed into the Milky Way's center in a sparkling image released in late June.
Scientists have found evidence that gravitational waves from a spectacular black hole collision carry signals from the very edge of the newly formed black hole. If confirmed by future observations, the discovery could provide an entirely new way to investigate what happens in the immediate vicinity of a black hole without ever observing it directly.
In a new study, the researchers analyzed an exceptionally strong gravitational wave event known as GW250114. They identified a "direct wave," a subtle feature of the total gravitational wave signal predicted by theory but never previously detected in real data. The signal appears to contain information from extremely close to the black hole's event horizon, the boundary beyond which nothing, not even light, can escape.
The findings, published June 24 in the journal Nature, suggest that gravitational wave observatories may eventually allow astronomers to probe regions that have remained inaccessible since black holes were first predicted by Albert Einstein's theory of general relativity.
Listening to the edge of a black hole
Although astronomers have photographed the glowing material surrounding some supermassive black holes and have detected dozens of black hole mergers through gravitational waves, the event horizon itself has remained frustratingly difficult to study.
Unlike ordinary light, gravitational waves are tiny ripples in space-time produced when massive objects accelerate. They pass almost undisturbed through the universe, carrying information about violent cosmic events that would otherwise remain hidden.
According to study co-author Sizheng Ma, a postdoctoral researcher at the Perimeter Institute for Theoretical Physics in Canada, the newly identified signal offers a rare glimpse of what happens immediately after two black holes collide.
When two black holes merge, they release gravitational waves — ripples in the fabric of space time — throughout the universe. Studying these waves can provide information about the newly formed black hole. (Image credit: K. Thorne (Caltech) and T. Carnahan (NASA GSFC))
"When two black holes merge, they violently shake space-time itself," Ma told Live Science. "For a brief moment, the region very close to the newly formed black hole's horizon is swept into a fast, fading swirl."
Ma explained that the direct wave is the portion of the gravitational wave signal produced near the horizon and carries the imprint of that motion outward through space.
"That is why it is so interesting," he said. "It may let us 'listen' to what happens near the horizon, a region we cannot see directly with light."
A remarkable black hole collision
The team focused on GW250114, a black hole merger detected on Jan. 14, 2025, by the two Laser Interferometer Gravitational-Wave Observatory (LIGO) detectors in Hanford, Washington, and Livingston, Louisiana.
"Our earlier theoretical work predicted that black hole mergers should produce a direct-wave signal from the near-horizon region," Ma said. "The big question was whether this effect could actually be seen in real data."
GW250114 turned out to provide exactly the conditions needed to test that prediction.
"It was strong enough, clean enough, and close enough to the theoretical situation where this signal should be visible," he said.
To search for the elusive feature, the researchers first removed the best-understood part of the gravitational wave signal, which comes from the newly formed black hole settling down after the merger. Then, they examined the remaining data to determine whether it consisted only of detector noise or contained another physical signal.
"What we found was striking," Ma said. "The remaining signal followed the expected rhythm and fading pattern of a wave shaped by the region very close to the final black hole's horizon."
The team concluded that the leftover signal matches the behavior expected for a direct wave predicted by previous theoretical studies.
ESA's upcoming LISA mission will detect gravitational waves from space, offering even more insights into the mysterious ripples than Earth-based detectors currently can. (Image credit: All About Space/Getty Images)
A new way to explore extreme gravity
The researchers stressed that their findings do not reveal what lies inside a black hole. Instead, they're providing a new observational tool for investigating the region immediately outside the event horizon.
"The gravitational wave data appear to carry an imprint from very close to the newly formed black hole's horizon — the famous point of no return," Ma said.
He explained that the measurements are consistent with space-time near the horizon being rapidly dragged around by the spinning black hole while the signal fades because of the intense gravitational field.
"For us, the exciting message is that gravitational waves may be giving us a new way to study the edge of a black hole using real observational data," Ma said.
Ma believes the method could eventually become useful for exploring ideas such as quantum gravity — which seeks to unite Einstein's theory of gravity with quantum mechanics — or the black hole information paradox, the longstanding puzzle of whether information that falls into a black hole is truly lost. However, it cannot test those questions directly yet.
"If quantum effects, or any deviations from the standard black-hole picture, leave a measurable imprint there, then direct waves could, in principle, help us search for them in the future," he said.
More observations will be needed
The researchers cautioned that the discovery is based on a single gravitational wave event. While GW250114 provided exceptionally favorable conditions, much stronger evidence will come only if similar signals are found in many additional black hole mergers.
"There are two main directions," Ma said. "The first is theory."
Current models capture the essential physics but remain simplified, and more realistic descriptions of black hole mergers will be needed.
"The second is observation," he added. "This result comes from one exceptionally loud and clean event, so the strongest confirmation would come from seeing the same kind of pattern in other black hole mergers."
As gravitational wave observatories continue to improve and detect increasing numbers of mergers, researchers hope to determine whether direct waves are a universal feature of black hole collisions.
"If the pattern appears repeatedly in the way general relativity predicts," Ma said, "direct waves could become a new way to study black hole horizons or the regions very close to them, and to test Einstein's theory in one of the most extreme environments in the universe."
If future observations confirm the team's results, scientists may have gained something they have sought for decades: a direct observational window into the very edge of a black hole.
See how much you know about black holes with our black hole quiz!
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In the late 2010s, astronomers were getting hints of something strange going on in the early universe. Using the most powerful telescopes on the ground, we were able to find black holes in the centers of some of the most distant galaxies. The light from these active galactic nuclei (AGNs) was emitted over 12 billion years ago, revealing conditions close to the beginning of cosmic time.
To an astronomer, that’s the mundane part. I’m only half joking — thousands of AGNs had already been identified in the previous half century. However, the most distant of these sources were startling because their central black holes appeared much more massive than expected. To be specific, we know how much mass black holes can start with, and we can write down equations to predict how quickly they should grow. The AGNs we observed seemed to violate these predictions. This raised some serious questions and was highlighted as a major point of inquiry to focus on going into the 2020s.
Then JWST launched, and the mystery grew deeper. No matter where we looked, enormous black holes kept cropping up in astonishing numbers. Astronomers who model the universe with equations and computer simulations have tried to explain these results, but this has been a serious challenge. Some researchers have broken the emergency glass and reached for a highly theoretical tool: the direct-collapse black hole. Unlike the normal pathway for forming black holes (the deaths of massive stars), this model suggests that an enormous cloud of gas could directly collapse into a black hole without forming a star at all. The resulting black holes could have as much mass as a hundred thousand Suns put together — orders of magnitude more than a “normal” black hole. Although this pathway can explain the presence of huge black holes so early in the universe’s history, we’ve never directly seen this happen, so for now it remains just a theoretical possibility.
However, if direct-collapse black holes were widespread at early times, there is one indirect signature we might be able to detect: a large population of intermediate-mass black holes with masses between a hundred thousand and a million times that of the Sun. If we can find such a population, we’ll have strong evidence for the direct-collapse model. Let’s go looking!
Intermediate Mass, Impossible Difficulty
Identifying intermediate-mass black holes requires a tricky combination of spectral resolution and sensitivity. Light from an object must be examined very finely in order to detect the telltale features of an intermediate-mass black hole. However, these sources are already quite faint, so spreading their emission this thin means that any potential signal is very likely to get lost in the noise.
The authors of today’s article use an unprecedented set of observations to leap over this hurdle and directly probe intermediate-mass black holes. They not only use the most sensitive spectroscopic instrument (NIRSpec) on the most powerful space telescope (JWST), but they take advantage of a phenomenon known as gravitational lensing.
According to Einstein’s general theory of relativity, gravity is the result of matter curving spacetime. Areas with more concentrated matter will experience stronger curvature. When an object traveling in a completely straight line moves through curved space, its path appears bent. This same effect happens to light. Intriguingly, a large concentration of matter can redirect diverging rays of light to a focus, acting like an enormous magnifying glass.
Astronomers take advantage of gravitational lensing by pointing telescopes at massive clusters of galaxies. The intense gravity of these regions can magnify sources in the background by tens or even hundreds of times. Galaxies that would be impossibly faint to see under normal conditions can thus be observed if they are strongly lensed, making this a powerful technique to examine otherwise hidden objects.
Putting Faint AGNs Under a Lens
The Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) program took extremely powerful observations of a galaxy cluster called Abell S1063 using JWST. The long exposure time, combined with the lensing power of the cluster, allows extremely faint sources in the background to be seen in unprecedented detail. The researchers scoured the data to search for signs of active black hole growth in the observed galaxies. Specifically, they carefully studied the emission lines in the spectrum of each object.
Normally, emission lines appear narrow. However, gas surrounding a massive black hole circulates at rapid speeds. A phenomenon known as the Doppler effect then comes into play. This is the same effect responsible for the characteristic rise and fall in the pitch of a siren from an emergency vehicle passing by. Emission from gas moving toward our line of sight appears bluer than it otherwise would, and gas moving away from us appears redshifted. The net effect is that a single emission line is widened, and we see characteristic “broad wings.” The width of the emission line can be used to estimate the mass of the central black hole, where broader wings imply a more massive black hole.
The researchers uncover 10 AGNs that display broadened Balmer series lines. Strikingly, they estimate that these galaxies have central black holes with masses as low as 400,000 times that of the Sun. While that might sound like a lot, it’s practically nothing compared to the monstrous 100-million-solar-mass black holes that JWST consistently turns up in other studies. Detecting such lightweight black holes, pushing into the realm of intermediate-mass black holes, is only possible due to the incredible sensitivity of these observations.
The researchers also compute what’s known as the black hole mass function. This is a measure of how many black holes exist at each mass. In other words, the black hole mass function measures how common lightweight black holes are compared to heavy ones. The mass function computed in this work and several other points of comparison are shown in Figure 1.
Figure 1: A comparison of black hole mass functions from various previous works and today’s article. The red hexagons are data points computed using the AGNs observed in this work, while blue circles and yellow squares are measurements computed using AGNs observed in previous articles. The red, green, and blue shaded areas represent the expected black hole mass function from various theoretical models. [Adapted from Fei et al. 2026]
Because the AGNs analyzed in today’s article host central black holes with much lower masses than any that have been observed in the past (at this early time in the universe), the authors are able to probe a completely new region of the black hole mass function. As seen in Figure 1, the leftmost red hexagon (lowest-mass data point) deviates from the roughly straight line traced by the other data points. This suggests that there are substantially more black holes with a few hundred thousand solar masses than previously expected.
Amazingly, this is exactly the measurement you would get if direct-collapse black holes (the hypothetical kind of massive black holes mentioned earlier in this article) were common in the early universe. If you scatter huge seeds across a large field, then you shouldn’t be surprised to see a sea of barely larger plants a few months later. Likewise, since these black holes start off so massive, they only need to grow a tiny bit to reach the threshold of that first red hexagon.
So is this proof that the early universe was filled with direct-collapse black holes, with this study probing the tip of an astonishing iceberg? It’s too early to tell for sure. While this is certainly an exciting result that sheds light on a previously unexplored population of objects, one can only do so much with a sample size of 10. More follow-up observations will be needed to measure the black hole mass function more precisely. Still, it’s amazing to think how much has changed in just a few years. JWST continues to provide unprecedented insight into some of the most breathtaking questions in all of astronomy.
Original astrobite edited by Tori Bonidie.
About the author, Ansh Gupta:
I’m an astronomy graduate student at the University of Texas at Austin working with Steven Finkelstein. I use data from JWST to study the formation and growth of the first galaxies and black holes in the universe. In my spare time, I enjoy playing piano, reading, and making YouTube videos.
A new study reveals why black holes let out massive radio "burps" years after eating stars, giving astronomers a chemical blueprint to predict them early.
Astronomers have created a comprehensive census of active galactic nuclei (AGN) — galaxies powered by a feeding central black hole. The new census, led by data pipeline developer Mugdha Polimera at the Center for Astrophysics | Harvard & Smithsonian, began while she was a graduate student at the University of North Carolina at Chapel Hill,Continue reading "Active black holes are more common than we thought"
How supermassive black holes (SMBH) in the center of galaxies accrete material, how they feedback into the surrounding region, and how they regulate these to influence the evolution of their galaxies are all hot topics in astronomical/astrophysical research. Astronomers are nearly certain that all large galaxies like the Milky Way have a SMBH, and detailed […]
Zooming through the galaxy faster than they should, hypervelocity stars are a curious population of stars whose origins are often difficult to determine. A recent study presents the first evidence of an old, low-mass hypervelocity star launched from the Milky Way’s center, providing clues into this elusive set of fast-moving stars.
Astronomers have caught a number of hypervelocity stars zipping through the Milky Way since their first discovery in 2005. With speeds fast enough to escape the galaxy, hypervelocity stars were launched off course by some strong dynamical interaction. One such method, known as the Hills mechanism, predicts that when a binary star system approaches the Milky Way’s central supermassive black hole, one binary member is captured by the black hole and the other is flung away with high velocity.
However, constraining a hypervelocity star’s origin to the galactic center is limited by uncertainties in distances and proper motions, muddling how well researchers have been able to trace their orbits backward. Among a number of candidate galactic center–origin hypervelocity stars, only one has been confidently identified as having been kicked from the galaxy’s center. Intriguingly, this hypervelocity star and most galactic center–origin candidates are young, massive stars — old, low-mass hypervelocity stars from the galactic center have yet to be identified.
What does this dearth of old, low-mass zooming stars mean? Either stars in the galactic center are preferentially young and massive, with fewer than expected old and small stars, or low-mass hypervelocity stars are missed by selection effects, challenging to detect in current surveys. Searching for hypervelocity stars with higher precision and sensitivity may allow astronomers to tease out this missing population and trace back more zooming stars to a Hills mechanism origin.
Discovering An Old Hypervelocity Star
Leveraging high-quality spectra from the Dark Energy Spectroscopic Instrument (DESI) survey and precise astrometry from Gaia, Shunhong Deng (University of Chinese Academy of Sciences; China West Normal University) and collaborators reported the discovery of the hypervelocity star DESI-HVS1. From the spectroscopic and astrometric analyses, the authors determined that DESI-HSV1 is a ~14-billion-year-old low-metallicity star with a mass about 80% that of the Sun’s, moving through the galaxy at 523 km/s.
Backward-integrated orbits of DESI-HVS1 for three different galactic potential models. The blue, red, and green points show the star’s current position, closest approach to the galactic center, and position 50 million years ago, respectively. Click to enlarge. [Deng et al 2026]
Exploring the possible origins of this hypervelocity star, the authors integrated the star’s orbit backward in time for one billion years. The backward orbit integrations show the star approaching the galactic center where it then turns around, traveling away faster than the local escape velocity of the galaxy. Even when varying the galactic potential and constants, all orbit integrations suggest DESI-HVS1’s motion through the galaxy is most naturally explained by the Hills mechanism.
While more refined galaxy models and comparison to other candidate galactic center–origin hypervelocity stars are necessary to fully confirm its origins, DESI-HVS1 provides the first compelling evidence for an old, low-mass hypervelocity star candidate consistent with a galactic center launch. This suggests that the observed lack of such stars is likely not a reflection of the Milky Way’s central stellar population, but rather a consequence of observational constraints making such small hypervelocity stars particularly difficult to detect. As large spectroscopic and astrometric surveys continue to advance, the sample of galactic-center hypervelocity star candidates will grow, enabling further exploration of the stellar environment and dynamical processes at the Milky Way’s core.
Citation
“An Old, Low-mass, Metal-poor Hypervelocity Star Candidate Consistent with Galactic Center Origin,” Shunhong Deng et al 2026 ApJL 1003 L9. doi:10.3847/2041-8213/ae6505
NASA Webb Finds Strongest Evidence Yet for ‘Black Hole Stars’
While the primary purpose of NASA’s James Webb Space Telescope’s observations of galaxy cluster Abell S1063 was to look for a certain population of stars, scientists obtained a detailed spectrum of GLIMPSE-17775 from the dataset. This little red dot is located behind Abell S1063.
Credits: Image: NASA, ESA, CSA, Vasily Kokorev (UT Austin); Image Processing: Alyssa Pagan (STScI)
The complex puzzle known as little red dots has become more complete since their initial discovery by NASA’s James Webb Space Telescope in 2022. Now a particular little red dot’s spectrum is helping connect many of the pieces.
A team of astronomers led by Vasily Kokorev at the University of Texas at Austin identified the lucky dot in question: GLIMPSE-17775. By carefully analyzing the dot’s spectrum captured by Webb — the deepest spectrum to date of a little red dot — the research team has identified multiple lines of evidence, all of which support the interpretation that GLIMPSE-17775 is a supermassive black hole enveloped in a dense cocoon of partially ionized gas, a model referred to as the BH* (black hole star) scenario. A paper describing the results was published today in The Astrophysical Journal.
“I think part of the scientific community is converging on a singular picture — that little red dots can be explained by black hole star models. But none of the previous little red dots have all of the pieces of evidence in the same place,” said Kokorev, lead author of the study. “With GLIMPSE-17775 we can test these models because of how deep and amazing this source’s spectrum is.”
Image: Abell S1063 with Pullout of GLIMPSE-17775 (NIRCam Image)
While the primary purpose of NASA’s James Webb Space Telescope’s observations of galaxy cluster Abell S1063 was to look for a certain population of stars, scientists obtained a detailed spectrum of GLIMPSE-17775 from the dataset. This little red dot is located behind Abell S1063.
Image: NASA, ESA, CSA, Vasily Kokorev (UT Austin); Image Processing: Alyssa Pagan (STScI)
Connecting puzzle pieces
Soon after Webb first began science operations, it discovered a new, mysterious type of object in the very early universe – abundant red objects that emerged about 600 million years after the big bang. Scientists have explored multiple explanations for these little red dots, including the black hole star scenario.
A set of fortunate circumstances brought about this new, elaborate spectrum of a little red dot. The little red dot that would come to be known as GLIMPSE-17775 was fortunately included in Webb’s imaging and spectroscopy efforts for a project that sought to look for Population III stars and faint galaxies in galaxy cluster Abell S1063. This little red dot is more distant than the galaxy cluster and magnified by gravitational lensing. (GLIMPSE-17775 has a cosmological redshift of 3.5, meaning it existed about 1.8 billion years after the big bang.)
While Webb provided a 30-hour spectrum of the little red dot, the effect of gravitational lensing made it equivalent to 80 hours of telescope time. This combination of Webb’s infrared sensitivity and nature’s own “magnifying glass” amplified the amount of detail that could be gleaned from GLIMPSE-17775. The result was more than 40 spectral lines from this small, red source, which is the most detailed little red dot spectrum to date.
“When we saw the spectrum for the first time, it was like having all the pieces of a puzzle scattered on the floor,” said Kokorev. “We picked up each piece of the puzzle, measured the lines, and started combining the different pieces into a mosaic. Maybe a few pieces looked like nothing at first, but then a couple of them came together, and we realized that there was something there.”
The spectroscopic data collected by Webb contains multiple lines of evidence that support the interpretation that little red dot GLIMPSE-17775 is a black hole star: a rapidly accreting, or growing, black hole enveloped in a dense gas cocoon, which is reprocessing the light emitted from near the black hole and producing the features seen in the spectrum.
Image: Evidence of a ‘Black Hole Star’
NASA’s James Webb Space Telescope captured the deepest spectrum to date of a little red dot. More than 40 spectral lines have been discerned from the data, many of which independently support the theory that GLIMPSE-17775 is a black hole enshrouded by a hot, dense gas cocoon.
Illustration: NASA, ESA, CSA, Vasily Kokorev (UT Austin); Designer: Leah Hustak (STScI)
Lines of evidence
Among the 40-plus lines that the team detected in GLIMPSE-17775’s spectrum were various independent indicators that all align with the BH* scenario. For example, the team found that many of the spectral lines, such as hydrogen, oxygen, and helium, do not fit a simple model of a rotating gas cloud. Instead, the best fit model includes a broadening effect known as electron scattering, a telltale sign that a dense, layered gas cocoon is enshrouding this source.
The strength and ratios of certain lines to each other, most notably the 16 iron lines that compose what the team has dubbed an “iron forest” and certain oxygen lines, require a high-energy source to produce them, like a rapidly accreting black hole. Additionally, astronomers noted the fluorescence and absorption of helium in the spectrum, both of which individually suggest that there is a dense medium enveloping a powerful source.
The BH* scenario not only fits GLIMPSE-17775; it also accounts for why most little red dots are faint in X-rays, since any such emission is likely absorbed by the dense gas cocoon.
One missing element of the GLIMPSE-17775 puzzle piece is the part of the spectrum that would reveal what’s known as a Balmer break, or a strong dip in the emitted light that’s a signature characteristic of little red dots. To build a more comprehensive understanding of this little red dot, the team incorporated ancillary data from two observing programs that used NASA’s Hubble Space Telescope: the Frontier Fields and BUFFALO (Beyond Ultra-deep Frontier Fields And Legacy Observations) programs.
The Webb and Hubble data together help explain why the Balmer break is weaker than what typically is found in other little red dots: A giant host galaxy is surrounding GLIMPSE-17775. Although a little red dot’s host galaxy is not something that has been usually seen at such scale before, it isn’t inconsistent with the dense gas cocoon model. The black hole star model of little red dots attributes excess blue light to stars in the host galaxy.
When Webb first discovered little red dots, some researchers thought these objects had “broken cosmology,” unsure how galaxies could have grown so big so quickly in the early universe to account for all this light coming from their stars. However, the team believes the GLIMPSE-17775 puzzle piece fits nicely in the existing framework of the universe’s evolutionary history, because black hole masses don’t need to be as high in order to explain the broad emission lines.
“Everything fits, nothing is broken, and I think that makes the puzzle that is our universe even better,” said Kokorev. “Looking ahead, I’m eager to dive deeper and learn about what is powering the central engines of little red dots. While we think it’s a black hole, there are some other interesting theories being proposed, which is exciting. Maybe in a year or two, we’ll have the final answer to what powers these sources.”
The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).
The following sections contain links to download this article’s images and videos in all available resolutions followed by related information links, media contacts, and if available, research paper and Spanish translation links.
Related Images & Videos
Abell S1063 with Pullout of GLIMPSE-17775 (NIRCam Image)
While the primary purpose of NASA’s James Webb Space Telescope’s observations of galaxy cluster Abell S1063 was to look for a certain population of stars, scientists obtained a detailed spectrum of GLIMPSE-17775 from the dataset. This little red dot is located behind Abell S1063.
Evidence of a ‘Black Hole Star’
NASA’s James Webb Space Telescope captured the deepest spectrum to date of a little red dot. More than 40 spectral lines have been discerned from the data, many of which independently support the theory that GLIMPSE-17775 is a black hole enshrouded by a hot, dense gas cocoon.
NASA Webb Finds Strongest Evidence Yet for ‘Black Hole Stars’
While the primary purpose of NASA’s James Webb Space Telescope’s observations of galaxy cluster Abell S1063 was to look for a certain population of stars, scientists obtained a detailed spectrum of GLIMPSE-17775 from the dataset. This little red dot is located behind Abell S1063.
Credits: Image: NASA, ESA, CSA, Vasily Kokorev (UT Austin); Image Processing: Alyssa Pagan (STScI)
The complex puzzle known as little red dots has become more complete since their initial discovery by NASA’s James Webb Space Telescope in 2022. Now a particular little red dot’s spectrum is helping connect many of the pieces.
A team of astronomers led by Vasily Kokorev at the University of Texas at Austin identified the lucky dot in question: GLIMPSE-17775. By carefully analyzing the dot’s spectrum captured by Webb — the deepest spectrum to date of a little red dot — the research team has identified multiple lines of evidence, all of which support the interpretation that GLIMPSE-17775 is a supermassive black hole enveloped in a dense cocoon of partially ionized gas, a model referred to as the BH* (black hole star) scenario. A paper describing the results was published today in The Astrophysical Journal.
“I think part of the scientific community is converging on a singular picture — that little red dots can be explained by black hole star models. But none of the previous little red dots have all of the pieces of evidence in the same place,” said Kokorev, lead author of the study. “With GLIMPSE-17775 we can test these models because of how deep and amazing this source’s spectrum is.”
Image: Abell S1063 with Pullout of GLIMPSE-17775 (NIRCam Image)
While the primary purpose of NASA’s James Webb Space Telescope’s observations of galaxy cluster Abell S1063 was to look for a certain population of stars, scientists obtained a detailed spectrum of GLIMPSE-17775 from the dataset. This little red dot is located behind Abell S1063.
Image: NASA, ESA, CSA, Vasily Kokorev (UT Austin); Image Processing: Alyssa Pagan (STScI)
Connecting puzzle pieces
Soon after Webb first began science operations, it discovered a new, mysterious type of object in the very early universe – abundant red objects that emerged about 600 million years after the big bang. Scientists have explored multiple explanations for these little red dots, including the black hole star scenario.
A set of fortunate circumstances brought about this new, elaborate spectrum of a little red dot. The little red dot that would come to be known as GLIMPSE-17775 was fortunately included in Webb’s imaging and spectroscopy efforts for a project that sought to look for Population III stars and faint galaxies in galaxy cluster Abell S1063. This little red dot is more distant than the galaxy cluster and magnified by gravitational lensing. (GLIMPSE-17775 has a cosmological redshift of 3.5, meaning it existed about 1.8 billion years after the big bang.)
While Webb provided a 30-hour spectrum of the little red dot, the effect of gravitational lensing made it equivalent to 80 hours of telescope time. This combination of Webb’s infrared sensitivity and nature’s own “magnifying glass” amplified the amount of detail that could be gleaned from GLIMPSE-17775. The result was more than 40 spectral lines from this small, red source, which is the most detailed little red dot spectrum to date.
“When we saw the spectrum for the first time, it was like having all the pieces of a puzzle scattered on the floor,” said Kokorev. “We picked up each piece of the puzzle, measured the lines, and started combining the different pieces into a mosaic. Maybe a few pieces looked like nothing at first, but then a couple of them came together, and we realized that there was something there.”
The spectroscopic data collected by Webb contains multiple lines of evidence that support the interpretation that little red dot GLIMPSE-17775 is a black hole star: a rapidly accreting, or growing, black hole enveloped in a dense gas cocoon, which is reprocessing the light emitted from near the black hole and producing the features seen in the spectrum.
Image: Evidence of a ‘Black Hole Star’
NASA’s James Webb Space Telescope captured the deepest spectrum to date of a little red dot. More than 40 spectral lines have been discerned from the data, many of which independently support the theory that GLIMPSE-17775 is a black hole enshrouded by a hot, dense gas cocoon.
Illustration: NASA, ESA, CSA, Vasily Kokorev (UT Austin); Designer: Leah Hustak (STScI)
Lines of evidence
Among the 40-plus lines that the team detected in GLIMPSE-17775’s spectrum were various independent indicators that all align with the BH* scenario. For example, the team found that many of the spectral lines, such as hydrogen, oxygen, and helium, do not fit a simple model of a rotating gas cloud. Instead, the best fit model includes a broadening effect known as electron scattering, a telltale sign that a dense, layered gas cocoon is enshrouding this source.
The strength and ratios of certain lines to each other, most notably the 16 iron lines that compose what the team has dubbed an “iron forest” and certain oxygen lines, require a high-energy source to produce them, like a rapidly accreting black hole. Additionally, astronomers noted the fluorescence and absorption of helium in the spectrum, both of which individually suggest that there is a dense medium enveloping a powerful source.
The BH* scenario not only fits GLIMPSE-17775; it also accounts for why most little red dots are faint in X-rays, since any such emission is likely absorbed by the dense gas cocoon.
One missing element of the GLIMPSE-17775 puzzle piece is the part of the spectrum that would reveal what’s known as a Balmer break, or a strong dip in the emitted light that’s a signature characteristic of little red dots. To build a more comprehensive understanding of this little red dot, the team incorporated ancillary data from two observing programs that used NASA’s Hubble Space Telescope: the Frontier Fields and BUFFALO (Beyond Ultra-deep Frontier Fields And Legacy Observations) programs.
The Webb and Hubble data together help explain why the Balmer break is weaker than what typically is found in other little red dots: A giant host galaxy is surrounding GLIMPSE-17775. Although a little red dot’s host galaxy is not something that has been usually seen at such scale before, it isn’t inconsistent with the dense gas cocoon model. The black hole star model of little red dots attributes excess blue light to stars in the host galaxy.
When Webb first discovered little red dots, some researchers thought these objects had “broken cosmology,” unsure how galaxies could have grown so big so quickly in the early universe to account for all this light coming from their stars. However, the team believes the GLIMPSE-17775 puzzle piece fits nicely in the existing framework of the universe’s evolutionary history, because black hole masses don’t need to be as high in order to explain the broad emission lines.
“Everything fits, nothing is broken, and I think that makes the puzzle that is our universe even better,” said Kokorev. “Looking ahead, I’m eager to dive deeper and learn about what is powering the central engines of little red dots. While we think it’s a black hole, there are some other interesting theories being proposed, which is exciting. Maybe in a year or two, we’ll have the final answer to what powers these sources.”
The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).
The following sections contain links to download this article’s images and videos in all available resolutions followed by related information links, media contacts, and if available, research paper and Spanish translation links.
Related Images & Videos
Abell S1063 with Pullout of GLIMPSE-17775 (NIRCam Image)
While the primary purpose of NASA’s James Webb Space Telescope’s observations of galaxy cluster Abell S1063 was to look for a certain population of stars, scientists obtained a detailed spectrum of GLIMPSE-17775 from the dataset. This little red dot is located behind Abell S1063.
Evidence of a ‘Black Hole Star’
NASA’s James Webb Space Telescope captured the deepest spectrum to date of a little red dot. More than 40 spectral lines have been discerned from the data, many of which independently support the theory that GLIMPSE-17775 is a black hole enshrouded by a hot, dense gas cocoon.
What’s the story behind the longest gamma-ray burst ever observed? Researchers explore how repeated interactions between a white dwarf and an intermediate-mass black hole could explain GRB 250702B’s unusual properties.
In 2025, the Fermi Gamma-ray Space Telescope spotted an intense flash of gamma rays from a distant, dusty galaxy, and a fleet of spacefaring and earthbound telescopes soon revealed the remarkable characteristics of the event. GRB 250702B featured multiple bursts spanning several hours, individual flares lasting roughly 100 seconds, and X-ray emission in the 24 hours leading up to the gamma-ray activity — something never seen before in a gamma-ray burst.
These characteristics have been challenging to explain with typical models of long gamma-ray burst formation, such as collapsing massive stars, but researchers have developed numerous promising alternatives. In a new research article, astronomers have shown how GRB 250702B’s behavior might be explained by repeated close encounters between a white dwarf and an intermediate-mass black hole.
Eccentric Close Encounters
Yuri Sato (Tohoku University) and collaborators modeled the source of GRB 250702B as a white dwarf that has been captured into orbit around an intermediate-mass black hole. In their model, the white dwarf travels on an extremely eccentric orbit, drawing close to the black hole roughly once an hour. Each time the white dwarf ventures close, the black hole’s tidal forces strip away part of the star until, after about 40 such encounters, the white dwarf is completely destroyed.
Schematics showing the orbit of the white dwarf (WD; left) and the geometries that produce observable and unobservable jets. Click to enlarge. [Sato et al. 2026]
When the black hole peels material away from the white dwarf, some material swirls into an accretion disk, and some is cast off into space. Accretion from the disk powers a narrow relativistic jet: the source of the event’s powerful gamma-ray flares. This should mean that there is one jet produced each time the white dwarf is partially disrupted — 40 times — yet astronomers detected only a handful of flares from GRB 250702B.
Jet Precession and Model Predictions
The discrepancy can be resolved if the angle between the jet and the black hole’s spin axis precesses over time so that only some of the jets are pointed toward us. This can occur if the accretion disk is misaligned relative to the black hole’s spin. As an alternative, disk instabilities or other processes could keep all but a few of the expected jets from being launched.
Predicted strength of the radio afterglow for the jet precession case (maximum case) and the case in which only four jets were launched due to disk instabilities or jet choking (minimum case). The x-axis shows the time since the burst was detected in X-rays by the Einstein Probe (EP). [Sato et al. 2026]
Sato and coauthors found that these two scenarios have different long-term outcomes, providing a potential way to ascertain what’s going on at the source; in the jet precession scenario, the jets that are launched away from our line of sight produce an order of magnitude more radio emission at late times.
This work by Sato and collaborators demonstrates how the repeated partial tidal disruption of a white dwarf by an intermediate-mass black hole can match the properties of one of the most remarkable recent transient sources — one that has pushed astronomers to consider new ways of producing gamma-ray bursts.
Citation
“Successive Partial Disruptions with Orbital Precession in a White Dwarf–Black Hole System for Repeating GRB 250702B,” Yuri Sato et al 2026 ApJL1003 L44. doi:10.3847/2041-8213/ae6a8f
Astronomers have discovered a distant quasar powered by a feeding supermassive black hole blasting out winds at record-breaking speeds for such an outflow seen in ultraviolet light, traveling at 30% the speed of light.
By taking general relativity into higher dimensions, a trio of physicists has proven that a mathematical pattern of ripples in space-time geometry could give rise to naked singularities and microscopic black holes.
Where do black hole mergers happen? Recent research finds evidence that most black hole mergers occur in triple systems containing a close inner binary and a more distant third party.
Assembling Merging Black Holes
Thanks to the combined efforts of the LIGO, Virgo, and KAGRA gravitational wave detectors, we’ve now collected the subtle signals from several hundred pairs of merging stellar-mass black holes. As this collection of spacetime ripples continues to grow, researchers are seeking to understand how these merging black hole pairs were assembled.
In the simplest scenario, pairs of high-mass stars independently evolve into black holes, lose momentum by emitting gravitational waves, and meld into one another. But the population of merging black holes likely contains contributions from multiple sources, including multiple-star systems, the disks surrounding accreting supermassive black holes, and black holes that have already experienced a merger. Which of these merging populations is reflected in our catalog of gravitational wave events?
Modeling Challenges
A black hole binary system with aligned spins and orbit (top) and a binary with spins tilted by 90 degrees (bottom). [AAS Nova/Kerry Hensley]
In theory, this question can be answered by extracting the properties of merging black holes — mass, spin, and the like — from gravitational wave observations and comparing these properties against model predictions from different formation pathways. In reality, this is exceedingly difficult, as certain merger pathways can produce a wide variety of results, depending on assumptions or fine tuning.
So far, the increasingly large pool of gravitational wave detections tentatively points to a feature that could illuminate the sites of black hole mergers: a peak in the spin–orbit tilt distribution around 90 degrees. This feature has been most confidently extracted from nonparametric analyses, which do not make assumptions about the population of merging black holes, but it has also been hinted at in parametric analyses, which do make population-level assumptions.
Triple-System Feature
To investigate this feature further, a team led by Jakob Stegmann (Max Planck Institute for Astrophysics) performed a new, astrophysically motivated parametric analysis of the most recent catalog of gravitational wave detections from LIGO, Virgo, and KAGRA.
The three populations in the team’s modeling. [Stegmann et al. 2026]
Their modeling tests combinations of multiple populations, including mergers in isolated binary systems, triple-star systems, and dense environments like star clusters. They also include a potential contribution from higher-mass mergers involving black holes that have merged previously. Using this framework, Stegmann’s team found that the observed spin–orbit tilt distribution is best matched by a model dominated by mergers in triple-star systems, with some contribution from other sources.
Posterior predictive distribution of black hole spin–orbit tilts. Both the authors’ modeling (solid blue line) and the nonparametric modeling performed by the LIGO–Virgo–KAGRA collaboration (solid green line) find evidence for a peak in the spin–orbit tilt distribution near cosθ = 0. [Adapted from Stegmann et al. 2026]
Specifically, this finding suggests that most mergers occur in hierarchical triple systems, which naturally predict an excess of 90-degree spin–orbit tilts without any fine tuning. Hierarchical triples contain an inner close binary with a distant outer companion; in these systems, relativistic spin precession, gravitational wave emission, and oscillations in eccentricity and inclination work to tilt the black holes in the inner binary by 90 degrees.
Stegmann and collaborators pointed out that the triple-system scenario aligns well with other properties of the observed population of black hole mergers, such as the mass and effective spin distributions. This scenario may also be necessary to explain certain merging pairs that might have had slightly eccentric orbits at the moment of merging. If future gravitational wave observations strengthen the evidence for a peak in the spin–orbit tilt distribution near 90 degrees, it will have profound implications for how and where black holes merge in our universe.
Citation
“Gravitational-Wave Observations Suggest Most Black Hole Mergers Form in Triples,” Jakob Stegmann et al 2026 ApJL1000 L59. doi:10.3847/2041-8213/ae52ec
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