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Probing Binary Stars in the Small Magellanic Cloud with the JWST
Astronomers want to know how universal the initial mass fraction (IMF) of galaxies is. To do they that, they need to discern binary stars in other galaxies, a difficult task. Researchers used the JWST to study the Small Magellanic Cloud and determine how many binary stars are there, since they can confuse measurements of the IMF.
NASA Sets Coverage for August Northern Hemisphere Total Solar Eclipse
On Wednesday, Aug. 12, a total solar eclipse will be visible in parts of Greenland, Iceland, northern Russia, the Atlantic Ocean, Spain, and a small corner of Portugal. NASA will stream the eclipse live with views across the path and interviews with subject matter experts through a variety of platforms.
Learn where to watch online:
Viewers in other places in the Northern Hemisphere also will have the chance to experience a partial solar eclipse, including parts of the U.S. (from Alaska to North Carolina), most of Canada, much of Europe, and northwestern Africa.
During the eclipse, NASA will conduct experiments in the path of totality. To investigate the dynamics of the Sun’s corona, a NASA-funded science team will chase the Moon’s shadow with a WB-57 high-altitude research aircraft. The NASA-supported Nationwide Eclipse Ballooning Project is sending students from several U.S. universities to Iceland and Spain to launch scientific balloons before, during, and after the eclipse to research how the temporary darkening of our skies during the eclipse affects Earth’s atmosphere.
NASA’s eclipse coverage is as follows (all times Eastern):
Wednesday, Aug. 12
- 1:15 p.m.: Eclipse broadcast begins
- 1:45 p.m.: Totality begins in Iceland
- 2:28 p.m.: Totality begins in Spain
NASA photography coverage
Photos of the eclipse, dependent on visibility, will be available shortly after the eclipse. View images on the agency’s Flickr account.
Watch, engage on social media
During the broadcast, NASA experts will answer questions submitted on social media. Send in your questions and let people know you’re watching the eclipse on X, Facebook, and Instagram by following and tagging these accounts:
X: @NASA, @NASASolarSystem, @NASAScience_
Facebook: NASA, NASASolarSystem, @NASAScience
Instagram: @NASA, @NASASolarSystem, @NASAScience_
Learn more about the eclipse at:
https://science.nasa.gov/eclipses
-end-
Abbey Interrante / Karen Fox
Headquarters, Washington
301-201-0124 / 202-358-1600
abbey.a.interrante@nasa.gov / karen.c.fox@nasa.gov
NASA Sets Coverage for August Northern Hemisphere Total Solar Eclipse
On Wednesday, Aug. 12, a total solar eclipse will be visible in parts of Greenland, Iceland, northern Russia, the Atlantic Ocean, Spain, and a small corner of Portugal. NASA will stream the eclipse live with views across the path and interviews with subject matter experts through a variety of platforms.
Learn where to watch online:
Viewers in other places in the Northern Hemisphere also will have the chance to experience a partial solar eclipse, including parts of the U.S. (from Alaska to North Carolina), most of Canada, much of Europe, and northwestern Africa.
During the eclipse, NASA will conduct experiments in the path of totality. To investigate the dynamics of the Sun’s corona, a NASA-funded science team will chase the Moon’s shadow with a WB-57 high-altitude research aircraft. The NASA-supported Nationwide Eclipse Ballooning Project is sending students from several U.S. universities to Iceland and Spain to launch scientific balloons before, during, and after the eclipse to research how the temporary darkening of our skies during the eclipse affects Earth’s atmosphere.
NASA’s eclipse coverage is as follows (all times Eastern):
Wednesday, Aug. 12
- 1:15 p.m.: Eclipse broadcast begins
- 1:45 p.m.: Totality begins in Iceland
- 2:28 p.m.: Totality begins in Spain
NASA photography coverage
Photos of the eclipse, dependent on visibility, will be available shortly after the eclipse. View images on the agency’s Flickr account.
Watch, engage on social media
During the broadcast, NASA experts will answer questions submitted on social media. Send in your questions and let people know you’re watching the eclipse on X, Facebook, and Instagram by following and tagging these accounts:
X: @NASA, @NASASolarSystem, @NASAScience_
Facebook: NASA, NASASolarSystem, @NASAScience
Instagram: @NASA, @NASASolarSystem, @NASAScience_
Learn more about the eclipse at:
https://science.nasa.gov/eclipses
-end-
Abbey Interrante / Karen Fox
Headquarters, Washington
301-201-0124 / 202-358-1600
abbey.a.interrante@nasa.gov / karen.c.fox@nasa.gov
NASA’s Curiosity Views a Sand-Capped Butte
NASA/JPL-Caltech/MSSS Photojournal Navigation Downloads NASA’s Curiosity Views a Sand-Capped Butte
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NASA’s Curiosity Mars rover captured this sand-capped butte, nicknamed “Miraflores,” estimated to be about 20 feet (6 meters) tall, with its Mast Camera, or Mastcam, on June 11, 2026, the 4,923rd Martian day, or sol, of the mission. The butte was left behind as surrounding rock eroded away over time, deepening the broad valley Curiosity is climbing through.
The surrounding area includes an expanse of terrain covered in surface features called polygons.
The panorama is made up of 11 individual images that were sent to Earth and stitched together. The color has been adjusted to match lighting conditions as the human eye would see them on Earth.
Curiosity was built by NASA’s Jet Propulsion Laboratory, which is managed by Caltech in Pasadena, California. JPL leads the mission on behalf of NASA’s Science Mission Directorate in Washington as part of NASA’s Mars Exploration Program portfolio. Malin Space Science Systems in San Diego built and operates Mastcam.
To learn more about Curiosity, visit:
science.nasa.gov/mission/msl-curiosity
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NASA’s Curiosity Views a Sand-Capped Butte
NASA/JPL-Caltech/MSSS Photojournal Navigation Downloads NASA’s Curiosity Views a Sand-Capped Butte
PNG (27.41 MB)
Description
NASA’s Curiosity Mars rover captured this sand-capped butte, nicknamed “Miraflores,” estimated to be about 20 feet (6 meters) tall, with its Mast Camera, or Mastcam, on June 11, 2026, the 4,923rd Martian day, or sol, of the mission. The butte was left behind as surrounding rock eroded away over time, deepening the broad valley Curiosity is climbing through.
The surrounding area includes an expanse of terrain covered in surface features called polygons.
The panorama is made up of 11 individual images that were sent to Earth and stitched together. The color has been adjusted to match lighting conditions as the human eye would see them on Earth.
Curiosity was built by NASA’s Jet Propulsion Laboratory, which is managed by Caltech in Pasadena, California. JPL leads the mission on behalf of NASA’s Science Mission Directorate in Washington as part of NASA’s Mars Exploration Program portfolio. Malin Space Science Systems in San Diego built and operates Mastcam.
To learn more about Curiosity, visit:
science.nasa.gov/mission/msl-curiosity
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NASA’s Curiosity Discovers a Field of Martian Polygons
NASA/JPL-Caltech/MSSS Photojournal Navigation Downloads NASA’s Curiosity Discovers a Field of Martian Polygons
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PIA26729 Figure A
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Description
NASA’s Curiosity Mars rover captured this 360-degree view of an expanse of terrain covered in surface features called polygons on June 19 and 20, 2026, the 4,930th and 4,931st Martian days, or sols, of the mission. The rover has found polygons several times in the past, but never so many in one place. Across the center of this image, the surface is covered by shapes ranging in size from roughly 2 to 4 inches (5 to 10 centimeters) in diameter. The features also surround and wrap around a sand-capped butte nicknamed “Miraflores,” seen at far right in the image.
Figure A
Figure A is a crop from the bottom-center of the panorama highlighting the polygons and their honeycomb-like textures.
Polygonal textures can form from a variety of conditions, including drying out of the surface (like in mud cracks), temperature cycles, compaction after being buried, or shrinkage of the sediment from loss of water or mineral changes. Scientists are measuring characteristics of these polygons to home in on which process formed them.
This panorama was captured by Curiosity’s Mast Camera, or Mastcam, as the rover continued its ascent of the foothills of Mount Sharp, a 3-mile-tall (5-kilometer-tall) mountain that it’s been climbing since 2014.
The panorama is made up of 340 individual images that were sent to Earth and stitched together. The color has been adjusted to match lighting conditions as the human eye would see them on Earth.
Curiosity was built by NASA’s Jet Propulsion Laboratory, which is managed by Caltech in Pasadena, California. JPL leads the mission on behalf of NASA’s Science Mission Directorate in Washington as part of NASA’s Mars Exploration Program portfolio. Malin Space Science Systems in San Diego built and operates Mastcam.
To learn more about Curiosity, visit:
science.nasa.gov/mission/msl-curiosity
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NASA’s Curiosity Discovers a Field of Martian Polygons
NASA/JPL-Caltech/MSSS Photojournal Navigation Downloads NASA’s Curiosity Discovers a Field of Martian Polygons
PNG (305.97 MB)
PIA26729 Figure A
PNG (3.37 MB)
Description
NASA’s Curiosity Mars rover captured this 360-degree view of an expanse of terrain covered in surface features called polygons on June 19 and 20, 2026, the 4,930th and 4,931st Martian days, or sols, of the mission. The rover has found polygons several times in the past, but never so many in one place. Across the center of this image, the surface is covered by shapes ranging in size from roughly 2 to 4 inches (5 to 10 centimeters) in diameter. The features also surround and wrap around a sand-capped butte nicknamed “Miraflores,” seen at far right in the image.
Figure AFigure A is a crop from the bottom-center of the panorama highlighting the polygons and their honeycomb-like textures.
Polygonal textures can form from a variety of conditions, including drying out of the surface (like in mud cracks), temperature cycles, compaction after being buried, or shrinkage of the sediment from loss of water or mineral changes. Scientists are measuring characteristics of these polygons to home in on which process formed them.
This panorama was captured by Curiosity’s Mast Camera, or Mastcam, as the rover continued its ascent of the foothills of Mount Sharp, a 3-mile-tall (5-kilometer-tall) mountain that it’s been climbing since 2014.
The panorama is made up of 340 individual images that were sent to Earth and stitched together. The color has been adjusted to match lighting conditions as the human eye would see them on Earth.
Curiosity was built by NASA’s Jet Propulsion Laboratory, which is managed by Caltech in Pasadena, California. JPL leads the mission on behalf of NASA’s Science Mission Directorate in Washington as part of NASA’s Mars Exploration Program portfolio. Malin Space Science Systems in San Diego built and operates Mastcam.
To learn more about Curiosity, visit:
science.nasa.gov/mission/msl-curiosity
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Understanding How Martian Auroras Are Made
NASA’s Curiosity Mars Rover Discovers Field of Honeycomb Textures
3 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater) NASA’s Curiosity Discovers a Field of Martian PolygonsNASA/JPL-Caltech/MSSS
As NASA’s Curiosity rover recently began climbing up a Martian valley nicknamed “Valle Grande,” it sent back images that were a familiar sight to mission scientists: honeycomb-like textures called polygonal fractures, each one about 1.5 to 3 inches (4 to 8 centimeters) across. The mission has spotted small patches of these geometric shapes several times before, but nothing at the scale discovered in Valle Grande.
In a 360-degree panorama that the rover captured on June 19 and 20, the 4,930th and 4,931st Martian days, or sols, of the mission, the polygonal shapes spread in all directions for as far as the rover can see. They even wrap around the sides of a nearby butte nicknamed “Miraflores,” which stands 20 feet (6 meters) tall and is topped with a thick cap of sand.
“We’ve seen a lot of fascinating landscapes through Curiosity’s eyes, but this sea of polygons took our breath away,” said the mission’s project scientist, Ashwin Vasavada of NASA’s Jet Propulsion Laboratory in Southern California. “We measured their shapes and chemistry carefully and are hopeful there are clues in the data as to how these features formed.”
A close-up of the polygon fractures discovered by NASA’s Curiosity Mars rover highlights their honeycomb-like texturesNASA/JPL-Caltech/MSSS
Some of the polygons that the mission has spotted in the past clearly formed as mud cracks, though a variety of processes can contribute to their honeycomb textures, including cycles of warm and cold temperatures or compression that squeezed water out of the sediment when the surface was buried.
These newly discovered polygons are among the many surprises Curiosity has trundled across since landing on Mars 14 years ago, on Aug. 5, 2012. Besides sulfur crystals, shiny meteorites, and other interesting geologic features, the rover has made major discoveries about the ancient Martian environment — most importantly, that it had the water, chemistry, and nutrients to support microbial life.
Billions of years ago, lakes and streams dappled the lower foothills of Mount Sharp, a 3-mile-tall (5-kilometer-tall) mountain that Curiosity has been ascending since 2014. The rover has previously uncovered chemistry left over from Mars’ watery history, including carbon-based molecules believed to be precursors to RNA and DNA, two nucleic acids that carry genetic information. Scientists have no way of knowing whether these organic molecules were created by biologic or geologic processes — either path is possible — but their discovery reconfirmed that ancient Mars had the right chemistry to support life.
NASA’s Curiosity Mars rover captured this sand-capped butte, nicknamed “Miraflores,” estimated to be about 20 feet (6 meters) tall, on June 11, 2026. The surrounding area includes an expanse of terrain covered in surface features called polygons.NASA/JPL-Caltech/MSSS
Managed by Caltech in Pasadena, JPL built Curiosity and leads the mission on behalf of NASA’s Science Mission Directorate in Washington as part of the agency’s Mars Exploration Program portfolio.
To learn more about Curiosity, visit:
https://science.nasa.gov/mission/msl-curiosity
News Media Contacts
Andrew Good
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-2433
andrew.c.good@jpl.nasa.gov
Karen Fox / Alana Johnson
NASA Headquarters, Washington
240-285-5155 / 202-672-4780
karen.c.fox@nasa.gov / alana.r.johnson@nasa.gov
2026-051
Share Details Last Updated Jul 29, 2026 Related Terms Explore More 5 min read NASA’s MAVEN Illuminates New Understanding of Auroras at MarsNASA MAVEN (Mars Atmosphere and Volatile Evolution) mission scientists have uncovered a key puzzle piece…
Article 1 week ago 5 min read NASA’s Juno Takes Temperature of Jupiter’s Fiery Moon Io Article 1 week ago 5 min read US-India Satellite Delivers Data, Reveals ‘Hummingbird’ in Antarctica Article 1 week ago Keep Exploring Discover Related Topics Mars Science Laboratory: Curiosity RoverPart of NASA’s Mars Science Laboratory mission, at the time of launch, Curiosity was the largest and most capable rover…
Curiosity Science HighlightsCuriosity Finds Evidence of Persistent Liquid Water in the Past Just after landing, Curiosity found smooth, rounded pebbles that likely…
Mars ExplorationMars is the only planet we know of inhabited entirely by robots. Learn more about the Mars Missions.
Planetary ScienceNASA’s planetary science program explores the objects in our solar system to better understand its history and the distribution of…
NASA’s Curiosity Mars Rover Discovers Field of Honeycomb Textures
3 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater) NASA’s Curiosity Discovers a Field of Martian PolygonsNASA/JPL-Caltech/MSSSAs NASA’s Curiosity rover recently began climbing up a Martian valley nicknamed “Valle Grande,” it sent back images that were a familiar sight to mission scientists: honeycomb-like textures called polygonal fractures, each one about 1.5 to 3 inches (4 to 8 centimeters) across. The mission has spotted small patches of these geometric shapes several times before, but nothing at the scale discovered in Valle Grande.
In a 360-degree panorama that the rover captured on June 19 and 20, the 4,930th and 4,931st Martian days, or sols, of the mission, the polygonal shapes spread in all directions for as far as the rover can see. They even wrap around the sides of a nearby butte nicknamed “Miraflores,” which stands 20 feet (6 meters) tall and is topped with a thick cap of sand.
“We’ve seen a lot of fascinating landscapes through Curiosity’s eyes, but this sea of polygons took our breath away,” said the mission’s project scientist, Ashwin Vasavada of NASA’s Jet Propulsion Laboratory in Southern California. “We measured their shapes and chemistry carefully and are hopeful there are clues in the data as to how these features formed.”
A close-up of the polygon fractures discovered by NASA’s Curiosity Mars rover highlights their honeycomb-like texturesNASA/JPL-Caltech/MSSSSome of the polygons that the mission has spotted in the past clearly formed as mud cracks, though a variety of processes can contribute to their honeycomb textures, including cycles of warm and cold temperatures or compression that squeezed water out of the sediment when the surface was buried.
These newly discovered polygons are among the many surprises Curiosity has trundled across since landing on Mars 14 years ago, on Aug. 5, 2012. Besides sulfur crystals, shiny meteorites, and other interesting geologic features, the rover has made major discoveries about the ancient Martian environment — most importantly, that it had the water, chemistry, and nutrients to support microbial life.
Billions of years ago, lakes and streams dappled the lower foothills of Mount Sharp, a 3-mile-tall (5-kilometer-tall) mountain that Curiosity has been ascending since 2014. The rover has previously uncovered chemistry left over from Mars’ watery history, including carbon-based molecules believed to be precursors to RNA and DNA, two nucleic acids that carry genetic information. Scientists have no way of knowing whether these organic molecules were created by biologic or geologic processes — either path is possible — but their discovery reconfirmed that ancient Mars had the right chemistry to support life.
NASA’s Curiosity Mars rover captured this sand-capped butte, nicknamed “Miraflores,” estimated to be about 20 feet (6 meters) tall, on June 11, 2026. The surrounding area includes an expanse of terrain covered in surface features called polygons.NASA/JPL-Caltech/MSSSManaged by Caltech in Pasadena, JPL built Curiosity and leads the mission on behalf of NASA’s Science Mission Directorate in Washington as part of the agency’s Mars Exploration Program portfolio.
To learn more about Curiosity, visit:
https://science.nasa.gov/mission/msl-curiosity
News Media Contacts
Andrew Good
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-2433
andrew.c.good@jpl.nasa.gov
Karen Fox / Alana Johnson
NASA Headquarters, Washington
240-285-5155 / 202-672-4780
karen.c.fox@nasa.gov / alana.r.johnson@nasa.gov
2026-051
Share Details Last Updated Jul 29, 2026 Related Terms Explore More 5 min read NASA’s MAVEN Illuminates New Understanding of Auroras at MarsNASA MAVEN (Mars Atmosphere and Volatile Evolution) mission scientists have uncovered a key puzzle piece…
Article 1 week ago 5 min read NASA’s Juno Takes Temperature of Jupiter’s Fiery Moon Io Article 1 week ago 5 min read US-India Satellite Delivers Data, Reveals ‘Hummingbird’ in Antarctica Article 1 week ago Keep Exploring Discover Related Topics Mars Science Laboratory: Curiosity RoverPart of NASA’s Mars Science Laboratory mission, at the time of launch, Curiosity was the largest and most capable rover…
Curiosity Science HighlightsCuriosity Finds Evidence of Persistent Liquid Water in the Past Just after landing, Curiosity found smooth, rounded pebbles that likely…
Mars ExplorationMars is the only planet we know of inhabited entirely by robots. Learn more about the Mars Missions.
Planetary ScienceNASA’s planetary science program explores the objects in our solar system to better understand its history and the distribution of…
APOD: 2026 July 29 – Psyche Receives Gravity Assist from Mars
APOD
Astronomy Picture of the Day
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Psyche Receives Gravity Assist from MarsExplanation: Solar System bodies make deep space exploration more fuel efficient! Today’s video shows the Psyche spacecraft gaining speed and changing its trajectory with minimal fuel spent due to a gravity assist from Mars in May 2026. Mars has an average orbital speed of almost 87,000 km/h (54,000 mph) around the Sun. Its orbital motion and its gravity allowed Mars to pull Psyche along with it, increasing the spacecraft’s speed. Gravity assists have been used since 1959’s Luna 3 mission to allow for spacecraft (the Voyagers, Cassini) to reach farther than they could with fuel alone. This assist helped the Psyche spacecraft on its journey to the Psyche asteroid, which it will reach in 2029. While passing Mars, the spacecraft tested instruments that will analyze the asteroid’s composition and magnetic field. This is the first mission to an asteroid thought to be largely made of metal, an essential building block for planets, rather than rock or ice.
Find dark skies and look up this August to witness the Perseids meteor shower uninhibited by the Moon!
Tomorrow’s picture: a red Sun
Date July 29, 2026 Credit NASA/JPL-Caltech/ASU/True Story Films Authors & editors: Robert Nemiroff, Jerry Bonnell, Cecilia Chirenti, Keighley Rockcliffe A service of: ASD at NASA / GSFC,NASA Science Activation & Michigan Tech. U.
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Yesterday’s Image APOD: 2026 July 28 – Barnards Loop over Twin Volcanoes
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Understanding How Martian Auroras Are Made
This July 23, 2026, illustration depicts charged particles from a solar storm stripping away charged particles of Mars’ atmosphere, one of the processes of Martian atmosphere loss studied by NASA’s MAVEN (Mars Atmosphere and Volatile Evolution) mission. NASA MAVEN mission scientists have found that certain types of auroras on Mars form in a similar way to Earth-based auroras.
Read more about this discovery.
Image credit: NASA
Understanding How Martian Auroras Are Made
This July 23, 2026, illustration depicts charged particles from a solar storm stripping away charged particles of Mars’ atmosphere, one of the processes of Martian atmosphere loss studied by NASA’s MAVEN (Mars Atmosphere and Volatile Evolution) mission. NASA MAVEN mission scientists have found that certain types of auroras on Mars form in a similar way to Earth-based auroras.
Read more about this discovery.
Image credit: NASA
Hundreds of ancient, never-before-seen ‘earthworks’ discovered in the Amazon
Many of these structures date to around C.E. 100–300, during the time of the Aquiry civilization, and may have been used for ceremonial purposes
A unique cellular trick may explain octopus intelligence
A newly discovered change in ribosomal RNA makes protein production more precise, potentially safeguarding these cephalopods’ complex nervous systems
ESCAPADE Images Earth and Moon From Its Temporary Home
Sometimes, you have embark on a journey to appreciate home. The Escape and Plasma Acceleration and Dynamics Explorers (ESCAPADE) mission recently gave us just such a view of our homeworld and our large natural satellite, as seen from the spacecrafts’ temporary orbit around the Sun-Earth L2 Lagrange point.
Jupiter’s Moon Io is Surprisingly Fluffy
Ash from countless volcanic eruptions on Io have likely built up its porous surface.
The post Jupiter’s Moon Io is Surprisingly Fluffy appeared first on Sky & Telescope.
Astronomers spot best-yet example of a wandering supermassive black hole
Giant black holes adrift in deep space are normally invisible—unless they’re dining on stars
NASA Webb Explores Family Tree of Newly Discovered Distant Objects
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Image: NASA, ESA, CSA, STScI, Pierluigi Rinaldi (Steward Observatory); Image Processing: Alyssa Pagan (STScI)
Since their discovery by NASA’s James Webb Space Telescope in 2022, little red dots (LRDs) have been the subject of great interest to astronomers. Understanding the nature of these extremely distant, compact red sources has been a puzzling scientific endeavor.
One popular theory is that little red dots are supermassive black holes known as active galactic nuclei, although they display characteristics unlike nearby active galactic nuclei. While they appear abundant at high redshift early in the universe, they rapidly decrease in number at lower redshifts. (The higher the redshift, the greater the distance the light has traveled across the universe.) This perplexing shift in number raises the question: What happens to little red dots as the universe matures?
A team of researchers led by Pierluigi Rinaldi of the University of Arizona’s Steward Observatory, now at the Space Telescope Science Institute (STScI) in Baltimore, has built upon their previous research in a new study published on July 29 in The Astrophysical Journal and proposed one pathway LRDs can follow as the universe ages: Though they may look like a unique galaxy population, these dots are affected by observational bias — some features just don’t appear at higher redshifts with current technology.
Image: Saguaro in GOODS-North Field (NIRCam) Scientists have proposed one pathway little red dots can follow as the universe matures based on their analysis of spiral galaxy WISEA J123635.56+621424.2, nicknamed the “Saguaro.” They suggest little red dots may be a temporary phase of highly active supermassive black holes. Image: NASA, ESA, CSA, STScI, Pierluigi Rinaldi (Steward Observatory); Image Processing: Alyssa Pagan (STScI)
Their conclusions are based on their analysis of lower-redshift spiral galaxy WISEA J123635.56+621424.2, nicknamed the “Saguaro” for its prominent arms, like the cactus native to the Sonoran Desert in the Southwestern United States. A particularly intriguing feature of this redshift 2 galaxy, which corresponds to approximately 3.3 billion years after the big bang, is its little red dot-like center that is reminiscent of the ruby red fruit produced by the desert plant.
“Everything created in the early universe must evolve into something around us. We have had little idea of what LRDs become, but these results finally show us how to find their progeny,” said co-author George Rieke of the University of Arizona. Previous studies by NASA’s retired Spitzer Space Telescope provided the first hint of the dust-obscured, compact galaxy population in the lower-redshift universe that the Saguaro belongs to, paving the way for NASA’s Hubble and James Webb space telescopes’ high-resolution analyses.
“The Saguaro is important because it’s a prototypical little red dot and is one of the few we have found at lower redshift. It can be used to study the pathway of these dots throughout cosmic time,” said Fabio Pacucci of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, and a co-author of the study.
Among the thousands of sources Rinaldi looked at across several surveys, the Saguaro was an example of the right place — with one of Webb’s microshutter arrays perfectly framed over the galaxy’s core to take spectroscopic data — and right time — being at lower redshift. To get as broad a view of the spiral galaxy as possible across the electromagnetic spectrum, the team used Hubble’s ultraviolet- and Webb’s infrared-imaging and spectroscopic archival data, respectively.
“Because the Saguaro is at lower redshift, we can see the very beautiful and bright host galaxy in high resolution and detail with Webb and Hubble,” said Zihao Wu of the Harvard-Smithsonian Center for Astrophysics, and a co-author of the study. “Webb’s observations can help us understand how the galaxy and its little red dot-like nucleus are connected.”
The team took multiple approaches to verify that the Saguaro’s compact red nucleus matched the characteristics of a prototypical LRD. In particular, the Hubble and Webb data showed that the nucleus is brighter in both ultraviolet and infrared light than in visible light, just like distant LRDs. The team also carefully disentangled the light emitted from the host and nucleus, and considered the presence of X-ray emission from the source.
Although the majority of little red dots at high redshift are not detectable in X-ray light, NASA’s Chandra X-ray Observatory detected weak X-ray emission from the Saguaro.
“What the X-ray light observations show is that this galaxy has an active galactic nucleus, and a very obscured one at that,” said Carys Gilbert, a Master’s student at the University of Cape Town in South Africa and a co-author of the paper. “It’s not only obscured but also X-ray weak. That kind of combination could explain the lack of X-ray emission that we see from all other little red dots. It fits the puzzle of little red dots nicely.”
In addition to demonstrating how the Saguaro’s central compact red source fits the little red dot criteria, the team synthetically shifted the galaxy to a higher redshift to explore how this galactic environment would appear to observers if located in the early universe. As expected, the Saguaro’s surrounding galactic structure fades so that only the bright, LRD-like source at its center is visible.
“Our theory is that most of these distant sources are affected by this cosmological effect, creating an observational bias,” said Rinaldi. “We simply are not able to sample the immediate environment of high-redshift little red dots because their surroundings are just too faint to be observed even with Webb. Little red dots are far more complex than just being a dot. They’re just the tip of the iceberg — of a supermassive black hole interacting with its nearby surroundings.”
Image: Little Red Dot at Redshift 2: Real and Simulated Graphic Scientists synthetically shifted the Saguaro, a lower-redshift spiral galaxy, to a higher redshift to find out how it would appear if it was in the early universe. Its compact red appearance suggests that little red dots are a phase of highly active supermassive black holes. Image: NASA, ESA, CSA, Pierluigi Rinaldi (Steward Observatory); Image Processing: Alyssa Pagan (STScI); Illustration: Leah Hustak (STScI)
Considering the Saguaro case study, the team believes that LRDs may not be a unique galaxy population, but instead a temporary phase of highly active supermassive black holes. Could this theory be the link between the populous high-redshift little red dots seen by Webb and the local universe?
While the Saguaro is not representative of all LRDs, the team proposes that this is one phase of these compact red sources. To build more confidence, further study of the Saguaro is necessary, as well as seeking other Saguaro-like galaxies at lower redshift. The team also intends to comb through Webb’s bountiful archival data to build a census of little red dots to study how their environments may impact how they mature. These different approaches are all geared to helping uncover the family tree of little red dots.
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 Hubble Space Telescope has been operating for over three decades and continues to make ground-breaking discoveries that shape our fundamental understanding of the universe. Hubble is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope and mission operations. Lockheed Martin Space, based in Denver, also supports mission operations at Goddard. The Space Telescope Science Institute in Baltimore, which is operated by the Association of Universities for Research in Astronomy, conducts Hubble science operations for NASA.
To learn more about Webb, visit:
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Related Images & Videos Saguaro in GOODS-North Field (NIRCam)Scientists have proposed one pathway little red dots can follow as the universe matures based on their analysis of spiral galaxy WISEA J123635.56+621424.2, nicknamed the “Saguaro.” They suggest little red dots may be a temporary phase of highly active supermassive black holes.
Little Red Dot at Redshift 2: Real and Simulated Graphic
Scientists synthetically shifted the Saguaro, a lower-redshift spiral galaxy, to a higher redshift to find out how it would appear if it was in the early universe. Its compact red appearance suggests that little red dots are a phase of highly active supermassive black holes.
Related Links
Read more: Webb Science: Galaxies Through Time
Read more: Galaxies Over Time
Explore more: ViewSpace: Connecting Little Red Dots
Watch: Sonification of Gas Velocity Around a Supermassive Black Hole
Watch: JWST Science Simulations: Galaxy Formation
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Contact Media
Laura Betz
NASA’s Goddard Space Flight Center
Greenbelt, Maryland
laura.e.betz@nasa.gov
Abigail Major
Space Telescope Science Institute
Baltimore, Maryland
Hannah Braun
Space Telescope Science Institute
Baltimore, Maryland
Related Terms Keep Exploring Related Topics James Webb Space Telescope
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