Normal view
Scientists Develop a New Way To Measure Gravitational Waves in the Expanding Universe
Astronomers Find Strongest Evidence Yet for Magnetic Fields on Alien Worlds
Astronomers Unveil Record-Breaking Haul of 161 New Black Hole Collisions
Hubble Sees Swarm of Galaxies
2 min read
Hubble Sees Swarm of Galaxies

Looking somewhat like a swarm of bees returning to their hive, this NASA Hubble Space Telescope image features the galaxy cluster MACS0329-0211. Galaxy clusters like MACS0329-0211 are important signposts in the story of how the structure of the universe evolved, and are the ultimate telescopic lenses, placing gravitationally lensed galaxies from the earliest stages of the universe into our view.
Zoom into this galaxy swarm and you will find large, oval-shaped elliptical galaxies, and thin spiral and lenticular galaxies viewed from the edge. We can also see the full, face-on view of spiral galaxies and their curving spiral arms. The image’s upper-right quadrant holds faint arcs of distant galaxies gravitationally lensed by the cluster’s massive gravity. The largest of these arcs appears above the bright oval shape of a giant elliptical galaxy. Closer inspection of the image’s center reveals several bright-white intersecting curves that appear as a distorted figure eight. This may be another distant galaxy whose light was magnified and distorted by this massive cluster’s gravity.
Hubble looked at MACS0329-0211 as part of an observing program of X-ray bright galaxy clusters. Researchers used Hubble’s two main cameras, the Advanced Camera for Surveys and its Wide Field Camera 3, to gather data visible and infrared light from the cluster. Hubble’s ability to see such a broad spectrum of light makes it a valuable tool in understanding the very nature of these galaxy clusters.
Media Contact:
Claire Andreoli
NASA’s Goddard Space Flight Center, Greenbelt, MD
claire.andreoli@nasa.gov
Details
Discover More Topics From Hubble
Hubble Sees Swarm of Galaxies
2 min read
Hubble Sees Swarm of Galaxies

Looking somewhat like a swarm of bees returning to their hive, this NASA Hubble Space Telescope image features the galaxy cluster MACS0329-0211. Galaxy clusters like MACS0329-0211 are important signposts in the story of how the structure of the universe evolved, and are the ultimate telescopic lenses, placing gravitationally lensed galaxies from the earliest stages of the universe into our view.
Zoom into this galaxy swarm and you will find large, oval-shaped elliptical galaxies, and thin spiral and lenticular galaxies viewed from the edge. We can also see the full, face-on view of spiral galaxies and their curving spiral arms. The image’s upper-right quadrant holds faint arcs of distant galaxies gravitationally lensed by the cluster’s massive gravity. The largest of these arcs appears above the bright oval shape of a giant elliptical galaxy. Closer inspection of the image’s center reveals several bright-white intersecting curves that appear as a distorted figure eight. This may be another distant galaxy whose light was magnified and distorted by this massive cluster’s gravity.
Hubble looked at MACS0329-0211 as part of an observing program of X-ray bright galaxy clusters. Researchers used Hubble’s two main cameras, the Advanced Camera for Surveys and its Wide Field Camera 3, to gather data visible and infrared light from the cluster. Hubble’s ability to see such a broad spectrum of light makes it a valuable tool in understanding the very nature of these galaxy clusters.
Media Contact:
Claire Andreoli
NASA’s Goddard Space Flight Center, Greenbelt, MD
claire.andreoli@nasa.gov
Discover More Topics From Hubble
The post Hubble Sees Swarm of Galaxies appeared first on NASA Science.
NASA’s Chandra Discovers Possible Supernova Remnant in Galactic Center
NASA’s Chandra Discovers Possible Supernova Remnant in Galactic Center

Using data from NASA’s Chandra X-ray Observatory, astronomers may have found a supernova remnant in an intriguing neighborhood in the middle of our galaxy. A paper describing these new findings published in The Astrophysical Journal.
Supernova remnants are the expanding remains of exploded stars and provide elements – like iron, oxygen, and silicon – that are critical for the formation of planets and for life as we know it to form and flourish.
This new supernova remnant, if confirmed, would be one of the closest ever discovered to the supermassive black hole at the central region of the Milky Way galaxy, an exotic region crammed with massive stars, long threads of magnetic fields and dense clouds of gas orbiting rapidly around the Galactic Center.

A new composite image of this region contains X-rays from Chandra and ESA’s (European Space Agency’s) XMM-Newton mission (shown in blue) as well as radio data from the MeerKAT telescope (shown in red) in South Africa. These have been combined with an optical image from the Pan-STARRS telescopes in Hawaii (red, green, and blue). The plane of the galaxy runs horizontally from left to right in the image, and the central black hole is off to the left of the image.
The evidence for the new supernova remnant, located about 26,000 light-years from Earth, comes from X-ray data from Chandra and XMM-Newton. The X-ray data reveals a “blob” of X-ray emission that may come from the remains of a massive star that self-destructed as a supernova, buried within the larger cloud of expanding gas.
The location of this suspected supernova remnant in the image is labeled with a circle.
It is in a bubble of gas that has had electrons stripped away from hydrogen – called an “H II region” – surrounding a massive, young star. This bubble is a bright source of radio emission called Sagittarius C.
If this is indeed a supernova remnant, then it is expanding at about two million miles per hour and is at least about 1,700 years old. Previously, observations with NASA’s now-retired SOFIA (Stratospheric Observatory for Infrared Astronomy) mission had shown evidence for an expanding shell of gas surrounding Sagittarius C. This gave astronomers a hint that a stellar explosion had occurred in the same spot.
The long filaments seen in the radio image are caused by energetic particles travelling along magnetic fields that are mostly directed perpendicular to the plane of the galaxy.
The nuclear fusion engines of stars create elements from hydrogen and helium that were abundant at the beginning of the universe. When stars explode at the end of their lives as supernovae, they send these newly synthesized elements into interstellar space and provide material for the next generation of stars and planets.
The team of astronomers searched the X-ray data for signs of increased amounts of key elements in the remnant, which would have been caused by the stellar explosion blasting them into space. While they did not see an enhancement, this could imply that the stellar debris has already mixed with the surrounding gas.
An alternative explanation for the X-ray blob is that the hot gas comes from a collection of massive stars in the region. The authors of the recent study don’t think this explanation is likely, because the X-ray emission from the blob is more than ten times brighter than the X-ray emission of large, known stellar clusters with bright, massive stars.
An additional image shows data from NASA’s James Webb Space Telescope added to the X-ray and radio data. The light blue color represents infrared light from gas in the H II region, and the darker blue depicts X-rays from the supernova remnant candidate, on the right side of the image. X-rays near the center of the image are associated with the H II region, possibly caused by material blown away by massive stars that has heated gas to millions of degrees, producing X-rays.
The study’s authors are Zhenlin Zhu and Mark Morris of the University of California, Los Angeles; Gabriele Ponti of Italy’s National Institute for Astrophysics; and Ping Zhou of Nanjing University in China.
NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program. The Smithsonian Astrophysical Observatory’s Chandra X-ray Center controls science operations from Cambridge, Massachusetts, and flight operations from Burlington, Massachusetts.
Visual Description
This release features a composite image of colorful, overlapping clouds, which suggests to astronomers that a supernova remnant may be buried in gas near the center of our Milky Way galaxy.
Set against a backdrop packed with distant stars and other specks of light are two distinct, overlapping clouds. The larger, visually dominant cloud, is red and multifaceted. It has an irregular shape, and features patches of different textures, including pockets that resemble wispy smoke, tangles of faint red veins, and clear streaking lines. This large cloud of expanding gas represents radio data from the MeerKAT telescope in South Africa.
Overlapping with that red cloud is a cloudy blue blob representing X-ray data from NASA’s Chandra X-ray Observatory and ESA’s XMM-Newton. Astronomers suggest that this blue blob of X-ray emissions is the remains of a massive star destroyed by a supernova.
Read more from NASA’s Chandra X-ray Observatory
To learn more about NASA’s Chandra mission, visit:
https://science.nasa.gov/chandra
News Media Contact
Megan Watzke
Chandra X-ray Center
Cambridge, Mass.
617-496-7998
mwatzke@cfa.harvard.edu
Joel Wallace
Marshall Space Flight Center, Huntsville, Alabama
256-544-0034
joel.w.wallace@nasa.gov
About the Author
Lee Mohon
Details
Explore More
Discover More Topics From NASA
Chandra X-ray Observatory

IXPE
The Imaging X-ray Polarimetry Explorer (IXPE) is NASA’s first mission to study the polarization of X-rays.

James Webb Space Telescope
Webb is the premier observatory of the next decade, serving thousands of astronomers worldwide. It studies every phase in the…

Hubble Space Telescope
Since its 1990 launch, the Hubble Space Telescope has changed our fundamental understanding of the universe.

The post NASA’s Chandra Discovers Possible Supernova Remnant in Galactic Center appeared first on NASA Science.
NASA’s Chandra Discovers Possible Supernova Remnant in Galactic Center
NASA’s Chandra Discovers Possible Supernova Remnant in Galactic Center

Using data from NASA’s Chandra X-ray Observatory, astronomers may have found a supernova remnant in an intriguing neighborhood in the middle of our galaxy. A paper describing these new findings published in The Astrophysical Journal.
Supernova remnants are the expanding remains of exploded stars and provide elements – like iron, oxygen, and silicon – that are critical for the formation of planets and for life as we know it to form and flourish.
This new supernova remnant, if confirmed, would be one of the closest ever discovered to the supermassive black hole at the central region of the Milky Way galaxy, an exotic region crammed with massive stars, long threads of magnetic fields and dense clouds of gas orbiting rapidly around the Galactic Center.

A new composite image of this region contains X-rays from Chandra and ESA’s (European Space Agency’s) XMM-Newton mission (shown in blue) as well as radio data from the MeerKAT telescope (shown in red) in South Africa. These have been combined with an optical image from the Pan-STARRS telescopes in Hawaii (red, green, and blue). The plane of the galaxy runs horizontally from left to right in the image, and the central black hole is off to the left of the image.
The evidence for the new supernova remnant, located about 26,000 light-years from Earth, comes from X-ray data from Chandra and XMM-Newton. The X-ray data reveals a “blob” of X-ray emission that may come from the remains of a massive star that self-destructed as a supernova, buried within the larger cloud of expanding gas.
The location of this suspected supernova remnant in the image is labeled with a circle.
It is in a bubble of gas that has had electrons stripped away from hydrogen – called an “H II region” – surrounding a massive, young star. This bubble is a bright source of radio emission called Sagittarius C.
If this is indeed a supernova remnant, then it is expanding at about two million miles per hour and is at least about 1,700 years old. Previously, observations with NASA’s now-retired SOFIA (Stratospheric Observatory for Infrared Astronomy) mission had shown evidence for an expanding shell of gas surrounding Sagittarius C. This gave astronomers a hint that a stellar explosion had occurred in the same spot.
The long filaments seen in the radio image are caused by energetic particles travelling along magnetic fields that are mostly directed perpendicular to the plane of the galaxy.
The nuclear fusion engines of stars create elements from hydrogen and helium that were abundant at the beginning of the universe. When stars explode at the end of their lives as supernovae, they send these newly synthesized elements into interstellar space and provide material for the next generation of stars and planets.
The team of astronomers searched the X-ray data for signs of increased amounts of key elements in the remnant, which would have been caused by the stellar explosion blasting them into space. While they did not see an enhancement, this could imply that the stellar debris has already mixed with the surrounding gas.
An alternative explanation for the X-ray blob is that the hot gas comes from a collection of massive stars in the region. The authors of the recent study don’t think this explanation is likely, because the X-ray emission from the blob is more than ten times brighter than the X-ray emission of large, known stellar clusters with bright, massive stars.
An additional image shows data from NASA’s James Webb Space Telescope added to the X-ray and radio data. The light blue color represents infrared light from gas in the H II region, and the darker blue depicts X-rays from the supernova remnant candidate, on the right side of the image. X-rays near the center of the image are associated with the H II region, possibly caused by material blown away by massive stars that has heated gas to millions of degrees, producing X-rays.
The study’s authors are Zhenlin Zhu and Mark Morris of the University of California, Los Angeles; Gabriele Ponti of Italy’s National Institute for Astrophysics; and Ping Zhou of Nanjing University in China.
NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program. The Smithsonian Astrophysical Observatory’s Chandra X-ray Center controls science operations from Cambridge, Massachusetts, and flight operations from Burlington, Massachusetts.
Visual Description
This release features a composite image of colorful, overlapping clouds, which suggests to astronomers that a supernova remnant may be buried in gas near the center of our Milky Way galaxy.
Set against a backdrop packed with distant stars and other specks of light are two distinct, overlapping clouds. The larger, visually dominant cloud, is red and multifaceted. It has an irregular shape, and features patches of different textures, including pockets that resemble wispy smoke, tangles of faint red veins, and clear streaking lines. This large cloud of expanding gas represents radio data from the MeerKAT telescope in South Africa.
Overlapping with that red cloud is a cloudy blue blob representing X-ray data from NASA’s Chandra X-ray Observatory and ESA’s XMM-Newton. Astronomers suggest that this blue blob of X-ray emissions is the remains of a massive star destroyed by a supernova.
Read more from NASA’s Chandra X-ray Observatory
To learn more about NASA’s Chandra mission, visit:
https://science.nasa.gov/chandra
News Media Contact
Megan Watzke
Chandra X-ray Center
Cambridge, Mass.
617-496-7998
mwatzke@cfa.harvard.edu
Joel Wallace
Marshall Space Flight Center, Huntsville, Alabama
256-544-0034
joel.w.wallace@nasa.gov
About the Author
Lee Mohon
Details
Explore More
Discover More Topics From NASA
Chandra X-ray Observatory

IXPE
The Imaging X-ray Polarimetry Explorer (IXPE) is NASA’s first mission to study the polarization of X-rays.

James Webb Space Telescope
Webb is the premier observatory of the next decade, serving thousands of astronomers worldwide. It studies every phase in the…

Hubble Space Telescope
Since its 1990 launch, the Hubble Space Telescope has changed our fundamental understanding of the universe.

The Strange “Spacetime Crystal” That Can Suddenly Turn Into a Black Hole
NASA Robotic Tech Demo Will Advance Prototype Gamma-Ray Detectors
4 min read
NASA Robotic Tech Demo Will Advance Prototype Gamma-Ray Detectors
A new type of gamma-ray sensor developed by NASA, called AstroPix, will take part in a robotic arm demonstration on the agency’s upcoming Fly Foundational Robots mission, set to launch in late 2027.
Gamma rays are the highest-energy form of light. Scientists observe them coming from events like lightning in Earth’s atmosphere, powerful solar flares from our Sun, and cosmic collisions in distant galaxies. The sensors on the AstroPix technology demonstration are designed to measure gamma rays between 20,000 and 700,000 electron volts. For comparison, visible light’s energy falls between 2 and 3 electron volts.
Current NASA missions, including the Fermi Gamma-ray Space Telescope and Neil Gehrels Swift Observatory, also observe gamma rays, including those with even higher energies.
But for energies between 500,000 to 1 million electron volts, existing detectors are less sensitive. This range is where many powerful explosions called gamma-ray bursts shine the brightest. It’s also where astronomers expect to see the strongest glow from the most massive and distant active galaxies powered by black holes. By stacking AstroPix detectors in future missions, scientists could bridge this gap and improve observations of these cosmic objects to better understand the processes that create and drive them.
“The Fly Foundational Robots spacecraft is also a technology demonstration, so the projects were a good fit for each other,” said Dan Violette, an AstroPix team member and post-doctoral fellow at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “We need to thoroughly test AstroPix’s performance before we can use the sensors in future science missions. We’ve flown comparable technologies on a scientific balloon mission, and the current prototype eventually will be part of a sounding rocket payload. Many of those flight opportunities only reach near space, though. It’s not often that technology demonstrations like ours can find a ride into orbit.”

Each AstroPix chip contains four silicon pixel gamma-ray detectors, and each detector incorporates 1,225 pixels. The chips function similarly to the sensors in cell phone cameras.
The AstroPix Satellite Technology dEmonstration Payload, also known as A-STEP, will be hosted within the Fly Foundational Robots mission’s Orbital Replacement Unit, a movable module built by Rocket Lab Robotics. Rocket Lab Robotics also will provide a robotic arm that will pick up and reposition the unit during flight and perform in-orbit operations as part of a robotic servicing demonstration. The A-STEP payload will collect its data following the repositioning. Astro Digital will provide the spacecraft.
The Orbital Replacement Unit was designed to support power and data interfaces for a payload, but the original plan called for the robotic arm to reposition the module without one. As mission development progressed, however, the Fly Foundational Robots team identified an opportunity to further maximize the mission’s value by integrating an additional technology demonstration that could fit within the 11.8-inch (30-centimeter) cube.
“The unit already had the volume, power, and data needed to support the AstroPix team’s design,” said Bo Naasz, senior technical lead, In-space Servicing, Assembly, and Manufacturing in the Space Technology Mission Directorate at NASA Headquarters in Washington. “One of our major goals with Fly Foundational Robots is to demonstrate robotic changeout of payloads in orbit, enabling upgrades or improvements to satellites and space instruments at a fraction of the cost of a full mission. Allowing AstroPix to complete its own technology demonstration in orbit is a bonus.”

The AstroPix team is working to deliver their hardware this September, and it will be integrated into the Fly Foundational Robots payload before final integration onto the spacecraft. The Orbital Replacement Unit will hold the chips and all the associated electronics needed to provide power, and collect and transmit data during flight.
NASA’s Fly Foundational Robots mission is funded through the Space Technology Mission Directorate’s ISAM portfolio, managed at NASA Goddard. Rocket Lab Robotics will supply the mission’s robotic arm system through a NASA Small Business Innovation Research Phase III award. Astro Digital will host the orbital flight test of the arm through NASA’s Flight Opportunities program, managed at NASA’s Armstrong Flight Research Center in Edwards, California. The development of AstroPix was supported by NASA’s Astrophysics Division in the Science Mission Directorate at NASA Headquarters, through the agency’s Astrophysics Research and Analysis Program, and funded through the Nancy Grace Roman Technology Fellowship.
To learn more, visit:
By Jeanette Kazmierczak
Goddard Space Flight Center, Greenbelt, Md.
Details
The post NASA Robotic Tech Demo Will Advance Prototype Gamma-Ray Detectors appeared first on NASA Science.
NASA Robotic Tech Demo Will Advance Prototype Gamma-Ray Detectors
4 min read
NASA Robotic Tech Demo Will Advance Prototype Gamma-Ray Detectors
A new type of gamma-ray sensor developed by NASA, called AstroPix, will take part in a robotic arm demonstration on the agency’s upcoming Fly Foundational Robots mission, set to launch in late 2027.
Gamma rays are the highest-energy form of light. Scientists observe them coming from events like lightning in Earth’s atmosphere, powerful solar flares from our Sun, and cosmic collisions in distant galaxies. The sensors on the AstroPix technology demonstration are designed to measure gamma rays between 20,000 and 700,000 electron volts. For comparison, visible light’s energy falls between 2 and 3 electron volts.
Current NASA missions, including the Fermi Gamma-ray Space Telescope and Neil Gehrels Swift Observatory, also observe gamma rays, including those with even higher energies.
But for energies between 500,000 to 1 million electron volts, existing detectors are less sensitive. This range is where many powerful explosions called gamma-ray bursts shine the brightest. It’s also where astronomers expect to see the strongest glow from the most massive and distant active galaxies powered by black holes. By stacking AstroPix detectors in future missions, scientists could bridge this gap and improve observations of these cosmic objects to better understand the processes that create and drive them.
“The Fly Foundational Robots spacecraft is also a technology demonstration, so the projects were a good fit for each other,” said Dan Violette, an AstroPix team member and post-doctoral fellow at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “We need to thoroughly test AstroPix’s performance before we can use the sensors in future science missions. We’ve flown comparable technologies on a scientific balloon mission, and the current prototype eventually will be part of a sounding rocket payload. Many of those flight opportunities only reach near space, though. It’s not often that technology demonstrations like ours can find a ride into orbit.”

Each AstroPix chip contains four silicon pixel gamma-ray detectors, and each detector incorporates 1,225 pixels. The chips function similarly to the sensors in cell phone cameras.
The AstroPix Satellite Technology dEmonstration Payload, also known as A-STEP, will be hosted within the Fly Foundational Robots mission’s Orbital Replacement Unit, a movable module built by Rocket Lab Robotics. Rocket Lab Robotics also will provide a robotic arm that will pick up and reposition the unit during flight and perform in-orbit operations as part of a robotic servicing demonstration. The A-STEP payload will collect its data following the repositioning. Astro Digital will provide the spacecraft.
The Orbital Replacement Unit was designed to support power and data interfaces for a payload, but the original plan called for the robotic arm to reposition the module without one. As mission development progressed, however, the Fly Foundational Robots team identified an opportunity to further maximize the mission’s value by integrating an additional technology demonstration that could fit within the 11.8-inch (30-centimeter) cube.
“The unit already had the volume, power, and data needed to support the AstroPix team’s design,” said Bo Naasz, senior technical lead, In-space Servicing, Assembly, and Manufacturing in the Space Technology Mission Directorate at NASA Headquarters in Washington. “One of our major goals with Fly Foundational Robots is to demonstrate robotic changeout of payloads in orbit, enabling upgrades or improvements to satellites and space instruments at a fraction of the cost of a full mission. Allowing AstroPix to complete its own technology demonstration in orbit is a bonus.”

The AstroPix team is working to deliver their hardware this September, and it will be integrated into the Fly Foundational Robots payload before final integration onto the spacecraft. The Orbital Replacement Unit will hold the chips and all the associated electronics needed to provide power, and collect and transmit data during flight.
NASA’s Fly Foundational Robots mission is funded through the Space Technology Mission Directorate’s ISAM portfolio, managed at NASA Goddard. Rocket Lab Robotics will supply the mission’s robotic arm system through a NASA Small Business Innovation Research Phase III award. Astro Digital will host the orbital flight test of the arm through NASA’s Flight Opportunities program, managed at NASA’s Armstrong Flight Research Center in Edwards, California. The development of AstroPix was supported by NASA’s Astrophysics Division in the Science Mission Directorate at NASA Headquarters, through the agency’s Astrophysics Research and Analysis Program, and funded through the Nancy Grace Roman Technology Fellowship.
To learn more, visit:
By Jeanette Kazmierczak
Goddard Space Flight Center, Greenbelt, Md.
Details
Physicists Are Rethinking Dark Matter… In The Wrong Way.
NASA Webb Finds Strongest Evidence Yet for ‘Black Hole Stars’
NASA Webb Finds Strongest Evidence Yet for ‘Black Hole Stars’

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)

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’

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).
To learn more about Webb, visit:
Downloads & Related Information
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.
Related Links
Read more: Black Hole Basics
Explore more: ViewSpace | Black Holes: Searching for the unseen
Watch: NASA Black Hole Visualization Takes Viewers Beyond the Brink
Watch: What Webb Learns from Light
Explore more: NASA’s Universe of Learning: Black Hole Resources
Read more: NASA Connects Little Red Dots with Chandra, Webb
Details
Laura Betz
NASA’s Goddard Space Flight Center
Greenbelt, Maryland
laura.e.betz@nasa.gov
Abigail Major
Space Telescope Science Institute
Baltimore, Maryland
Christine Pulliam
Space Telescope Science Institute
Baltimore, Maryland
NASA Webb Finds Strongest Evidence Yet for ‘Black Hole Stars’
NASA Webb Finds Strongest Evidence Yet for ‘Black Hole Stars’

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)

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’

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).
To learn more about Webb, visit:
Downloads & Related Information
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.
Related Links
Read more: Black Hole Basics
Explore more: ViewSpace | Black Holes: Searching for the unseen
Watch: NASA Black Hole Visualization Takes Viewers Beyond the Brink
Watch: What Webb Learns from Light
Explore more: NASA’s Universe of Learning: Black Hole Resources
Details
Laura Betz
NASA’s Goddard Space Flight Center
Greenbelt, Maryland
laura.e.betz@nasa.gov
Abigail Major
Space Telescope Science Institute
Baltimore, Maryland
Christine Pulliam
Space Telescope Science Institute
Baltimore, Maryland
The post NASA Webb Finds Strongest Evidence Yet for ‘Black Hole Stars’ appeared first on NASA Science.
June 9, 1988: First image of an Einstein ring
In early 1987, a team led by MIT’s Jacqueline Hewitt was imaging radio-emitting objects with the Very Large Array radio telescope as part of a gravitational lens survey. The unusual appearance of object MG1131+0456 – an oval with elongated bright spots at the ends – led to further investigation, and the researchers eventually concluded itContinue reading "June 9, 1988: First image of an Einstein ring"
The post June 9, 1988: First image of an Einstein ring appeared first on Astronomy Magazine.
Magnetic Fields May Solve a Longstanding Binary Star Mystery
Record-Breaking Black Hole Wind Blasts Through Space at 30% the Speed of Light
Astronomers Discover Two Monster Black Holes Creating a Cosmic Void as They Merge
- ZME Science
- A Rare “Cannibal” Solar Storm Will Push the Northern Lights South Tonight. You Might Just Catch Them!