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This planet survived the death of its star—and kept its atmosphere
Astronomers have for the first time observed an atmosphere around a giant planet orbiting a white dwarf
Webb studies how a planet survived the death of its star
An international team of astronomers has used the NASA/ESA/CSA James Webb Space Telescope to watch the Jupiter-sized exoplanet WD 1856 b transit its host star, measuring the planet’s mass and temperature and even detecting its atmosphere.
They found that the planet is significantly warmer than expected and determined how it most likely reached its very tight orbit around the star, a white dwarf. The results are our first window into the future of planets like Jupiter after the death of the Sun, billions of years into the future.
NASA’s Webb Studies How Planet Survived Death of its Star
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Artwork: NASA, ESA, CSA, Ralf Crawford (STScI)
NASA’s James Webb Space Telescope is giving us new insight into the far-future of solar systems like our own, as the agency continues to reveal the secrets of the universe and our place in it. Billions of years ago, a Sun-like star nearing the end of its life swelled tremendously in size to become a red giant before ejecting its outer layers, leaving a hot, remnant core known as a white dwarf. As a red giant, the star should have engulfed and destroyed any nearby planets. Yet astronomers have found a Jupiter-sized exoplanet orbiting the white dwarf every 34 hours at a separation of less than 2 million miles (3 million kilometers).
To solve the mystery of how this exoplanet survived, an international team of astronomers used NASA’s James Webb Space Telescope to watch the Jupiter-sized exoplanet WD 1856 b transit its host star, measuring the planet’s temperature and detecting molecules in its atmosphere. They found the planet is significantly warmer than expected and determined how it most likely reached its very tight orbit around the white dwarf star. The results are a window into the future of planets like Jupiter after the death of the Sun, billions of years into the future.
The results published Wednesday in the journal Nature.
WD 1856 b was discovered in 2020 by scientists using NASA’s TESS (Transiting Exoplanet Survey Satellite) and the retired Spitzer Space Telescope. It orbits the white dwarf WD 1856+534, which is located about 80 light-years from Earth. “The planet is about the size of Jupiter, but the white dwarf it orbits is the size of Earth, so the planet is seven times larger than its star,” said lead author Ryan MacDonald of the University of St. Andrews in the United Kingdom.
WD 1856 b orbits extremely close to its host star, a distance 50 times closer than Earth orbits the Sun. If WD 1856 b had originally been orbiting at that distance, it would have been obliterated while the star was a red giant. How did it survive the death of its host star and end up in its current position?
Image: Exoplanet WD 1856 b (Artist’s Concept) Exoplanet WD 1856 b, shown in this artist’s concept, is a gas giant that orbits its star at a distance 50 times closer than Earth orbits the Sun. Observations by NASA’s James Webb Space Telescope determined the planet’s temperature and detected molecules in its atmosphere. Artwork: NASA, ESA, CSA, Ralf Crawford (STScI) How big, how hot
The new study used Webb to watch the planet passing in front of its star. This transit yielded unique information about the planet’s mass, which is between four and eleven times the mass of Jupiter.
The team also was able to determine the planet’s temperature. During the transit, light from the star was partly blocked, but infrared light was reduced less than other wavelengths. The difference was infrared light emitted by the planet from its own heat. The data indicated that the planet has a temperature of about 260 degrees Fahrenheit (126 degrees Celsius) — significantly hotter than it would be if its only source of heat was the light from the white dwarf. This puzzling discovery turned out to be the key fact that proved how the planet must have reached its current orbit.
Christopher O’Connor of Northwestern University in Illinois, a co-author on the paper, was responsible for tracing the temperature of the planet back in time. O’Connor said, “The big question is how WD 1856 b ended up where it is today, and there are two theories. One is that the planet was swallowed by the host star as it was dying, and managed to survive on the inside. The other is that migration took place due to the gravitational effect of other objects in the system. The white dwarf is part of a triple star system, and the companion stars could have influenced WD 1856 b’s orbit.”
The researchers realized that there was no source of energy present to generate that heat today, so it must be residual energy from an earlier time when the planet was heated. Using models of how sub-stellar objects like WD 1856 b cool down over time, coupled with the new data from Webb, the team was able to project its temperature back in time and deduce how long ago the heating must have happened. The timing is key to determining whether the heating was from being engulfed by the red giant or occurred during an inward migration
They concluded that the heating most likely happened between 3 and 5.5 billion years after the star became a white dwarf. In this scenario, the planet was on a wide orbit that kept it safe from the star during its destructive red giant phase, and only migrated to its present location later on. “As the planet moved inward, its interactions with the strong gravity of the white dwarf will have caused it to warm up considerably, and it has been cooling ever since,” said O’Connor.
Light from the star passing through the planet’s atmosphere also picked up information about its chemical composition. “We saw the telltale signatures of small cloud particles and hydrocarbons, most likely methane, which is the first time we have seen an atmosphere on a planet transiting a dead star,” said co-author Victoria Boehm of Cornell University. “We recently observed four more transits of WD 1856 b with Webb to take a deeper look into its atmospheric chemistry and can’t wait to see the results.”
Image: Exoplanet WD 1856 b (Transmission Spectrum) NASA’s James Webb Space Telescope measured the constituents of exoplanet WD 1856 b as it passed in front of its star, finding signs of methane. WD 1856 b orbits a white dwarf star the size of Earth. As a result, the planet blocks more than half of the star’s light. Illustration: NASA, ESA, CSA, Joseph Olmsted (STScI) Solar system’s possible future
In approximately five billion years, the Sun will run out of hydrogen fuel in its core and swell up more than 100 times larger than it is now into a red giant star. It will then shed its outer layers and end its life as a white dwarf star. Mercury, Venus, and possibly the Earth will be destroyed by the red giant. However, the fate of the more distant planets, particularly the gas giants, is unclear. Finding and studying planets in orbit around the remnants of Sun-like stars after their death is a means of learning what might happen in our own solar system in the far future.
“We’re used to looking back in time when we use telescopes, but this is the first time we have been able to look forward to what might happen to the outer planets around the remnant of a Sun-like star,” said MacDonald. “It’s like using a time machine to peer into the distant future of our solar system.”
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 InformationThe 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 Exoplanet WD 1856 b (Artist’s Concept)Exoplanet WD 1856 b, shown in this artist’s concept, is a gas giant that orbits its star at a distance 50 times closer than Earth orbits the Sun. Observations by NASA’s James Webb Space Telescope determined the planet’s temperature and detected molecules in its atmosphere.
Exoplanet WD 1856 b (Transmission Spectrum)
NASA’s James Webb Space Telescope measured the constituents of exoplanet WD 1856 b as it passed in front of its star, finding signs of methane. WD 1856 b orbits a white dwarf star the size of Earth. As a result, the planet blocks more than half of the star’s light.
Related Links
Read more: Webb’s Impact on Exoplanet Research
Explore more: ViewSpace | Exoplanet Variety: Atmosphere
Explore more: How to Study Exoplanets: Webb and Challenges
Watch: Giant World Circles a Tiny Star
Explore more: ViewSpace | Star Death: Helix Nebula
More Webb: News | Images | Science | Home Page
Laura Betz
NASA’s Goddard Space Flight Center
Greenbelt, Maryland
laura.e.betz@nasa.gov
Bethany Downer
ESA/Webb
Baltimore, Maryland
Christine Pulliam
Space Telescope Science Institute
Baltimore, Maryland
Keep Exploring Related Topics James Webb Space Telescope
Webb is the premier observatory of the next decade, serving thousands of astronomers worldwide. It studies every phase in the…
Exoplanets
Exoplanet Stories
Stars
NASA’s Webb Studies How Planet Survived Death of its Star
- Webb
- News
- Overview
- Science
- Observatory
- Multimedia
- Team
- More
Artwork: NASA, ESA, CSA, Ralf Crawford (STScI)
NASA’s James Webb Space Telescope is giving us new insight into the far-future of solar systems like our own, as the agency continues to reveal the secrets of the universe and our place in it. Billions of years ago, a Sun-like star nearing the end of its life swelled tremendously in size to become a red giant before ejecting its outer layers, leaving a hot, remnant core known as a white dwarf. As a red giant, the star should have engulfed and destroyed any nearby planets. Yet astronomers have found a Jupiter-sized exoplanet orbiting the white dwarf every 34 hours at a separation of less than 2 million miles (3 million kilometers).
To solve the mystery of how this exoplanet survived, an international team of astronomers used NASA’s James Webb Space Telescope to watch the Jupiter-sized exoplanet WD 1856 b transit its host star, measuring the planet’s temperature and detecting molecules in its atmosphere. They found the planet is significantly warmer than expected and determined how it most likely reached its very tight orbit around the white dwarf star. The results are a window into the future of planets like Jupiter after the death of the Sun, billions of years into the future.
The results published Wednesday in the journal Nature.
WD 1856 b was discovered in 2020 by scientists using NASA’s TESS (Transiting Exoplanet Survey Satellite) and the retired Spitzer Space Telescope. It orbits the white dwarf WD 1856+534, which is located about 80 light-years from Earth. “The planet is about the size of Jupiter, but the white dwarf it orbits is the size of Earth, so the planet is seven times larger than its star,” said lead author Ryan MacDonald of the University of St. Andrews in the United Kingdom.
WD 1856 b orbits extremely close to its host star, a distance 50 times closer than Earth orbits the Sun. If WD 1856 b had originally been orbiting at that distance, it would have been obliterated while the star was a red giant. How did it survive the death of its host star and end up in its current position?
Image: Exoplanet WD 1856 b (Artist’s Concept) Exoplanet WD 1856 b, shown in this artist’s concept, is a gas giant that orbits its star at a distance 50 times closer than Earth orbits the Sun. Observations by NASA’s James Webb Space Telescope determined the planet’s temperature and detected molecules in its atmosphere. Artwork: NASA, ESA, CSA, Ralf Crawford (STScI) How big, how hotThe new study used Webb to watch the planet passing in front of its star. This transit yielded unique information about the planet’s mass, which is between four and eleven times the mass of Jupiter.
The team also was able to determine the planet’s temperature. During the transit, light from the star was partly blocked, but infrared light was reduced less than other wavelengths. The difference was infrared light emitted by the planet from its own heat. The data indicated that the planet has a temperature of about 260 degrees Fahrenheit (126 degrees Celsius) — significantly hotter than it would be if its only source of heat was the light from the white dwarf. This puzzling discovery turned out to be the key fact that proved how the planet must have reached its current orbit.
Christopher O’Connor of Northwestern University in Illinois, a co-author on the paper, was responsible for tracing the temperature of the planet back in time. O’Connor said, “The big question is how WD 1856 b ended up where it is today, and there are two theories. One is that the planet was swallowed by the host star as it was dying, and managed to survive on the inside. The other is that migration took place due to the gravitational effect of other objects in the system. The white dwarf is part of a triple star system, and the companion stars could have influenced WD 1856 b’s orbit.”
The researchers realized that there was no source of energy present to generate that heat today, so it must be residual energy from an earlier time when the planet was heated. Using models of how sub-stellar objects like WD 1856 b cool down over time, coupled with the new data from Webb, the team was able to project its temperature back in time and deduce how long ago the heating must have happened. The timing is key to determining whether the heating was from being engulfed by the red giant or occurred during an inward migration
They concluded that the heating most likely happened between 3 and 5.5 billion years after the star became a white dwarf. In this scenario, the planet was on a wide orbit that kept it safe from the star during its destructive red giant phase, and only migrated to its present location later on. “As the planet moved inward, its interactions with the strong gravity of the white dwarf will have caused it to warm up considerably, and it has been cooling ever since,” said O’Connor.
Light from the star passing through the planet’s atmosphere also picked up information about its chemical composition. “We saw the telltale signatures of small cloud particles and hydrocarbons, most likely methane, which is the first time we have seen an atmosphere on a planet transiting a dead star,” said co-author Victoria Boehm of Cornell University. “We recently observed four more transits of WD 1856 b with Webb to take a deeper look into its atmospheric chemistry and can’t wait to see the results.”
Image: Exoplanet WD 1856 b (Transmission Spectrum) NASA’s James Webb Space Telescope measured the constituents of exoplanet WD 1856 b as it passed in front of its star, finding signs of methane. WD 1856 b orbits a white dwarf star the size of Earth. As a result, the planet blocks more than half of the star’s light. Illustration: NASA, ESA, CSA, Joseph Olmsted (STScI) Solar system’s possible futureIn approximately five billion years, the Sun will run out of hydrogen fuel in its core and swell up more than 100 times larger than it is now into a red giant star. It will then shed its outer layers and end its life as a white dwarf star. Mercury, Venus, and possibly the Earth will be destroyed by the red giant. However, the fate of the more distant planets, particularly the gas giants, is unclear. Finding and studying planets in orbit around the remnants of Sun-like stars after their death is a means of learning what might happen in our own solar system in the far future.
“We’re used to looking back in time when we use telescopes, but this is the first time we have been able to look forward to what might happen to the outer planets around the remnant of a Sun-like star,” said MacDonald. “It’s like using a time machine to peer into the distant future of our solar system.”
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 InformationThe 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 Exoplanet WD 1856 b (Artist’s Concept)Exoplanet WD 1856 b, shown in this artist’s concept, is a gas giant that orbits its star at a distance 50 times closer than Earth orbits the Sun. Observations by NASA’s James Webb Space Telescope determined the planet’s temperature and detected molecules in its atmosphere.
Exoplanet WD 1856 b (Transmission Spectrum)
NASA’s James Webb Space Telescope measured the constituents of exoplanet WD 1856 b as it passed in front of its star, finding signs of methane. WD 1856 b orbits a white dwarf star the size of Earth. As a result, the planet blocks more than half of the star’s light.
Related Links
Read more: Webb’s Impact on Exoplanet Research
Explore more: ViewSpace | Exoplanet Variety: Atmosphere
Explore more: How to Study Exoplanets: Webb and Challenges
Watch: Giant World Circles a Tiny Star
Explore more: ViewSpace | Star Death: Helix Nebula
More Webb: News | Images | Science | Home Page
Laura Betz
NASA’s Goddard Space Flight Center
Greenbelt, Maryland
laura.e.betz@nasa.gov
Bethany Downer
ESA/Webb
Baltimore, Maryland
Christine Pulliam
Space Telescope Science Institute
Baltimore, Maryland
Keep Exploring Related Topics James Webb Space Telescope
Webb is the premier observatory of the next decade, serving thousands of astronomers worldwide. It studies every phase in the…
Exoplanets
Exoplanet Stories
Stars
Curiosity Blog, Sols 4934-4940: In the Land of the Polygons
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Curiosity Blog, Sols 4934-4940: In the Land of the Polygons NASA’s Mars rover Curiosity acquired this image of polygonal structures using its Mast Camera (Mastcam) on June 21, 2026 — Sol 4932, or Martian day 4,932 of the Mars Science Laboratory mission — at 14:57:55 UTC. NASA/JPL-Caltech/MSSS
Written by William Farrand, Senior Research Scientist, Space Science Institute
Earth planning date: Friday, June 26, 2026
There were two planning cycles over this span of sols. The Monday planning took place with Curiosity situated within a unit that from orbital imagery appeared light-toned, and from earlier rover positions appeared smooth. Reaching this unit, the rover team was surprised to see the unit covered with polygonal structures like the top of a giant Martian honeycomb. Driving further into the unit, the polygonal ridges were more eroded. Littered about this unit are pebble to cobble-sized dark-toned rocks. A still-to-be-resolved question is whether these are bits of Mars that “floated” down from higher in the stratigraphy, were ejected from distant impacts outside of Gale crater, or are meteorites from beyond Mars altogether. Examination of some previous dark “float” rocks indicated the presence of nickel, common in meteorites but less so in Martian rocks, but are all of the dark-toned pebbles and cobbles meteorites? Further investigations should help in answering this question.
Monday’s four-sol plan had APXS and MAHLI investigations looking at the ridges and centers of the polygons. The plan also included ChemCam Remote Micro-Imager (RMI) views of the “Miraflores” small knob and of the “Cordillera” mesa. Similar to the contact science activities, ChemCam LIBS measurements were focused on the polygons, with two measurements on different ridges and one on a polygon center. A ChemCam passive reflectance measurement of one of the aforementioned dark cobbles was also carried out. Environmental activities included a Navcam dust-devil search and atmospheric opacity (“tau”) measurements.
After driving further towards the upper boundary of the light-toned, polygon-covered unit, the three-sol Friday plan included APXS and MAHLI measurements of another polygon ridge and one of the dark-toned cobbles, “Cortadera.” ChemCam LIBS was also targeted on “Cortadera” and on a polygon ridge. ChemCam RMI was targeted on the top and base of the “Cordillera” mesa. Mastcam mosaics were planned of “Cordillera,” nearby troughs, part of the nearby “Valle Grande” channel, and documentation of LIBS targets and the Mastcam calibration target.
In the coming week, Curiosity will cross over into another band of materials which appear darker-toned in orbital images and rougher-textured, as viewed currently by the rover.
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Curiosity Blog, Sols 4934-4940: In the Land of the Polygons
- Curiosity Home
- Science
- News and Features
- Multimedia
- Mars Missions
- Mars Home
2 min read
Curiosity Blog, Sols 4934-4940: In the Land of the Polygons NASA’s Mars rover Curiosity acquired this image of polygonal structures using its Mast Camera (Mastcam) on June 21, 2026 — Sol 4932, or Martian day 4,932 of the Mars Science Laboratory mission — at 14:57:55 UTC. NASA/JPL-Caltech/MSSSWritten by William Farrand, Senior Research Scientist, Space Science Institute
Earth planning date: Friday, June 26, 2026
There were two planning cycles over this span of sols. The Monday planning took place with Curiosity situated within a unit that from orbital imagery appeared light-toned, and from earlier rover positions appeared smooth. Reaching this unit, the rover team was surprised to see the unit covered with polygonal structures like the top of a giant Martian honeycomb. Driving further into the unit, the polygonal ridges were more eroded. Littered about this unit are pebble to cobble-sized dark-toned rocks. A still-to-be-resolved question is whether these are bits of Mars that “floated” down from higher in the stratigraphy, were ejected from distant impacts outside of Gale crater, or are meteorites from beyond Mars altogether. Examination of some previous dark “float” rocks indicated the presence of nickel, common in meteorites but less so in Martian rocks, but are all of the dark-toned pebbles and cobbles meteorites? Further investigations should help in answering this question.
Monday’s four-sol plan had APXS and MAHLI investigations looking at the ridges and centers of the polygons. The plan also included ChemCam Remote Micro-Imager (RMI) views of the “Miraflores” small knob and of the “Cordillera” mesa. Similar to the contact science activities, ChemCam LIBS measurements were focused on the polygons, with two measurements on different ridges and one on a polygon center. A ChemCam passive reflectance measurement of one of the aforementioned dark cobbles was also carried out. Environmental activities included a Navcam dust-devil search and atmospheric opacity (“tau”) measurements.
After driving further towards the upper boundary of the light-toned, polygon-covered unit, the three-sol Friday plan included APXS and MAHLI measurements of another polygon ridge and one of the dark-toned cobbles, “Cortadera.” ChemCam LIBS was also targeted on “Cortadera” and on a polygon ridge. ChemCam RMI was targeted on the top and base of the “Cordillera” mesa. Mastcam mosaics were planned of “Cordillera,” nearby troughs, part of the nearby “Valle Grande” channel, and documentation of LIBS targets and the Mastcam calibration target.
In the coming week, Curiosity will cross over into another band of materials which appear darker-toned in orbital images and rougher-textured, as viewed currently by the rover.
-
Want to read more posts from the Curiosity team?
-
Want to learn more about Curiosity’s science instruments?
Article
1 week ago
3 min read Curiosity Blog, Sols 4920-4926: Surveying the Bands
Article
2 weeks ago
3 min read Curiosity Blog: Sols 4913-4919: Planetary Explorers, Freewheeling to the Yardang Unit!
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3 weeks ago
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Mars is the fourth planet from the Sun, and the seventh largest. It’s the only planet we know of inhabited…
All Mars Resources
Explore this collection of Mars images, videos, resources, PDFs, and toolkits. Discover valuable content designed to inform, educate, and inspire,…
Rover Basics
Each robotic explorer sent to the Red Planet has its own unique capabilities driven by science. Many attributes of a…
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The key to understanding the past, present or future potential for life on Mars can be found in NASA’s four…
Caltech Welcomes Astrophysicist Ray Jayawardhana as New President
Ray Jayawardhana begins his tenure today as the 10th president of the California Institute of Technology. His selection as Caltech’s president, and as the Sonja and William Davidow Presidential Chair and professor of astronomy, was announced Jan. 6. Jayawardhana succeeds Thomas Rosenbaum, who had served as Caltech’s president since 2014.
Founded in 1891, Caltech manages the Jet Propulsion Laboratory for NASA. The lab traces its origins to 1936, when a group of Caltech graduate students and other rocket enthusiasts began pioneering work in rocket propulsion. Once NASA was established in 1958, JPL became the space agency’s first and only federally funded research and development center.
“Today, I’m honored to begin my service as Caltech’s 10th president,” Jayawardhana wrote in his first message to the Caltech community. “Long before this day appeared on the horizon, Caltech and JPL have held a special place in my mind as beacons of humanity’s most ambitious acts of exploration and discovery.”
Looking ahead, Jayawardhana said he will be a fierce advocate for the Institute’s mission and the people who advance it, partnering with Caltech and JPL colleagues and other stakeholders to ensure the Institute will continue to have transformative impact on humanity. He also said he aims to pursue bold, catalytic investments in “blue-sky” ideas on campus, at JPL, and across the Institute’s suite of global observatories; enrich the educational experience of undergraduates, graduate students, and postdoctoral scholars; and expand the Institute’s engagement with the public.
“Dr. Jayawardhana steps into this role at a pivotal moment for Caltech, JPL, and NASA,” said Dave Gallagher, director of JPL. “We look forward to working closely with him on missions that will help define a new era of U.S. exploration — extending humanity’s reach into the solar system, unlocking extraordinary scientific discovery, and inspiring future generations to dare mighty things.”
Jayawardhana comes to Caltech from Johns Hopkins University, where as provost he oversaw the university’s 10 schools as well as an expansive portfolio of interdisciplinary programs, academic centers, and core administrative and operational units.
Prior to Johns Hopkins, he served as the Harold Tanner Dean of the College of Arts and Sciences and the Hans A. Bethe Professor and professor of astronomy at Cornell University. Earlier in his career, he was on the faculty at the University of Toronto, where he held a Canada Research Chair and served as senior adviser on science engagement to the university’s president. Jayawardhana earned his Ph.D. in astronomy from Harvard University and a B.S. in astronomy and physics from Yale University.
A pioneering astrophysicist, Jayawardhana investigates the origin and evolution of planets and planetary systems, as well as the formation of stars and brown dwarfs. Using the largest telescopes on the ground (including the W. M. Keck Observatory, which Caltech co-manages with the University of California) and in space (especially NASA’s James Webb Space Telescope), he and his collaborators use remote sensing to characterize planets outside our solar system, or exoplanets, with an eye toward assessing the prospects for life beyond Earth. He is a core science team member for the Near Infrared Imager and Slitless Spectrograph instrument aboard the Webb telescope, and his research group has led Gemini Observatory large programs on high-resolution spectroscopy of exoplanetary atmospheres.
Jayawardhana will continue his research alongside his presidential responsibilities as a Caltech professor of astronomy in the Division of Physics, Mathematics and Astronomy.
“Time and again, I’ve been struck not only by the audacity and brilliance of the work underway here, but also by this community of creative and original thinkers who seem constitutionally incapable of leaving the hardest questions unanswered,” Jayawardhana wrote in his note to the Caltech and JPL community.
The appointment marks a return to an early source of inspiration for the astrophysicist. Growing up as a self-described “space-obsessed kid” in Sri Lanka, Jayawardhana wrote to JPL asking for images from NASA’s Voyager and Viking missions (JPL manages Voyager and played a major role in Viking). A few weeks later, a package arrived at his childhood home.
“I still remember the thrill of finding the manila envelope waiting for me … with the unmistakable JPL logo,” he recalled in remarks to the JPL community in January. Inside was a viewbook filled with images of Jupiter and Saturn. “Holding it in my hands, I felt a rush of amazement, as if I were sharing in the grand quest to explore other worlds despite growing up in a remote corner of this one.”
Now, as Caltech’s president, that childhood inspiration has come full circle. “As an astrophysicist, I have the deepest respect for JPL’s enduring contributions to humanity’s quest to explore the solar system and beyond. And as Caltech’s president, I’m excited to work alongside you in that quest.”
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Matthew Segal
Jet Propulsion Laboratory, Pasadena, Calif.
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Caltech Welcomes Astrophysicist Ray Jayawardhana as New President
Ray Jayawardhana begins his tenure today as the 10th president of the California Institute of Technology. His selection as Caltech’s president, and as the Sonja and William Davidow Presidential Chair and professor of astronomy, was announced Jan. 6. Jayawardhana succeeds Thomas Rosenbaum, who had served as Caltech’s president since 2014.
Founded in 1891, Caltech manages the Jet Propulsion Laboratory for NASA. The lab traces its origins to 1936, when a group of Caltech graduate students and other rocket enthusiasts began pioneering work in rocket propulsion. Once NASA was established in 1958, JPL became the space agency’s first and only federally funded research and development center.
“Today, I’m honored to begin my service as Caltech’s 10th president,” Jayawardhana wrote in his first message to the Caltech community. “Long before this day appeared on the horizon, Caltech and JPL have held a special place in my mind as beacons of humanity’s most ambitious acts of exploration and discovery.”
Looking ahead, Jayawardhana said he will be a fierce advocate for the Institute’s mission and the people who advance it, partnering with Caltech and JPL colleagues and other stakeholders to ensure the Institute will continue to have transformative impact on humanity. He also said he aims to pursue bold, catalytic investments in “blue-sky” ideas on campus, at JPL, and across the Institute’s suite of global observatories; enrich the educational experience of undergraduates, graduate students, and postdoctoral scholars; and expand the Institute’s engagement with the public.
“Dr. Jayawardhana steps into this role at a pivotal moment for Caltech, JPL, and NASA,” said Dave Gallagher, director of JPL. “We look forward to working closely with him on missions that will help define a new era of U.S. exploration — extending humanity’s reach into the solar system, unlocking extraordinary scientific discovery, and inspiring future generations to dare mighty things.”
Jayawardhana comes to Caltech from Johns Hopkins University, where as provost he oversaw the university’s 10 schools as well as an expansive portfolio of interdisciplinary programs, academic centers, and core administrative and operational units.
Prior to Johns Hopkins, he served as the Harold Tanner Dean of the College of Arts and Sciences and the Hans A. Bethe Professor and professor of astronomy at Cornell University. Earlier in his career, he was on the faculty at the University of Toronto, where he held a Canada Research Chair and served as senior adviser on science engagement to the university’s president. Jayawardhana earned his Ph.D. in astronomy from Harvard University and a B.S. in astronomy and physics from Yale University.
A pioneering astrophysicist, Jayawardhana investigates the origin and evolution of planets and planetary systems, as well as the formation of stars and brown dwarfs. Using the largest telescopes on the ground (including the W. M. Keck Observatory, which Caltech co-manages with the University of California) and in space (especially NASA’s James Webb Space Telescope), he and his collaborators use remote sensing to characterize planets outside our solar system, or exoplanets, with an eye toward assessing the prospects for life beyond Earth. He is a core science team member for the Near Infrared Imager and Slitless Spectrograph instrument aboard the Webb telescope, and his research group has led Gemini Observatory large programs on high-resolution spectroscopy of exoplanetary atmospheres.
Jayawardhana will continue his research alongside his presidential responsibilities as a Caltech professor of astronomy in the Division of Physics, Mathematics and Astronomy.
“Time and again, I’ve been struck not only by the audacity and brilliance of the work underway here, but also by this community of creative and original thinkers who seem constitutionally incapable of leaving the hardest questions unanswered,” Jayawardhana wrote in his note to the Caltech and JPL community.
The appointment marks a return to an early source of inspiration for the astrophysicist. Growing up as a self-described “space-obsessed kid” in Sri Lanka, Jayawardhana wrote to JPL asking for images from NASA’s Voyager and Viking missions (JPL manages Voyager and played a major role in Viking). A few weeks later, a package arrived at his childhood home.
“I still remember the thrill of finding the manila envelope waiting for me … with the unmistakable JPL logo,” he recalled in remarks to the JPL community in January. Inside was a viewbook filled with images of Jupiter and Saturn. “Holding it in my hands, I felt a rush of amazement, as if I were sharing in the grand quest to explore other worlds despite growing up in a remote corner of this one.”
Now, as Caltech’s president, that childhood inspiration has come full circle. “As an astrophysicist, I have the deepest respect for JPL’s enduring contributions to humanity’s quest to explore the solar system and beyond. And as Caltech’s president, I’m excited to work alongside you in that quest.”
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Matthew Segal
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-8307
matthew.j.segal@jpl.nasa.gov
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NASA’s TESS Mission Finds Planetary System in New Way
NASA’s Goddard Space Flight Center
For the first time, NASA’s TESS (Transiting Exoplanet Survey Satellite) mission has identified a planet orbiting a distant star thanks to ripples in space-time. Unlike the star-hugging transiting planets TESS regularly reveals, the newfound world is a super-Jupiter orbiting far from its host star.
“When TESS launched, no one expected it to ever be capable of finding this kind of planet,” said Diana Dragomir, a professor at the University of New Mexico in Albuquerque and co-author of a paper describing the results. At 1.6 times Jupiter’s mass and a similar orbital distance, it would be extremely unlikely to find such a planet via the primary detection method TESS was designed for. “The discovery implies that there are probably other so-called microlensing planets hiding in TESS’s data that we hadn’t previously thought to look for.”
This artist’s concept visualizes Gaia23bra b, the first microlensing planet orbiting a distant star found by NASA’s TESS (Transiting Exoplanet Survey Satellite). This super-Jupiter orbits an orange dwarf star at a distance similar to Jupiter’s distance from the Sun. NASA’s Goddard Space Flight Center
Astronomers found the first hint of the planet, called Gaia23bra b, in 2023 using ESA’s (European Space Agency) now-retired Gaia space telescope. Gaia’s alert system flagged a star that brightened — something that can happen when a foreground star passes in front of a more distant one and magnifies its light through gravitational microlensing.
Researchers later looked back through archived TESS data and found TESS had caught it too.
“Gaia’s observations were too sparse to pick up on the planet,” said Mallory Harris, a Ph.D. candidate at the University of New Mexico, who led the study. “The TESS spacecraft happened to be monitoring the same area of the sky during the event, and its denser time coverage showed extra features in the light curve caused by a planet.”
The team’s analysis, published July 1 in The Astrophysical Journal Letters, revealed that Gaia23bra b, which orbits an orange dwarf star that’s about 80 percent of the Sun’s mass, is nearly 40,000 light-years away from Earth, far exceeding TESS’s usual search radius of about 150 light-years.
Microlensing 101Out of more than 6,000 known exoplanets (worlds outside our solar system), about three-fourths were discovered via the transit method, TESS’s typical planet-hunting technique. Astronomers monitor hordes of stars, watching for ones that periodically dim as orbiting planets cross in front of them — an event called a transit.
This animation illustrates the concept of gravitational microlensing. When one star in the sky (shown in the center of the animation) appears to pass nearly in front of another (located in the dashed circle at the right) from our vantage point, the light rays of the background star become bent due to the warped space-time around the foreground star. This star acts like a virtual magnifying glass, amplifying the brightness of the background star and causing its position to appear to slightly shift. If the nearer star harbors a planetary system, then those planets can also act as lenses, each one producing a short deviation in the brightness of the source. When astronomers find planets this way, they can measure their mass and orbital distance from their host star. NASA’s Goddard Space Flight Center/CI Lab
Microlensing has revealed less than 5% of known exoplanets. This light-bending phenomenon occurs when two stars align closely from our vantage point. Light from the more distant star curves as it travels through the warped space-time caused by the nearer star’s mass.
If the alignment is especially close, the nearer star acts like a cosmic lens, focusing and magnifying light from the background star. Planets orbiting the foreground star may also modify the distant star’s light, acting as their own tiny lenses. Astronomers see the effect as a spike in the star’s brightness.
The transit method is best at finding large planets orbiting very close to their host stars; large planets block the most starlight, while close-in planets are more likely to pass in front of the host star. These gargantuan, steamy worlds are fascinating to scientists, but astronomers want to find planets like those in our solar system, too. That’s microlensing’s specialty.
With microlensing, we can find smaller planets with greater orbital distances, including worlds in the habitable zone of their star and even farther away.Mallory harris
Ph.D. candidate at the University of New Mexico
Microlensing isn’t well suited to finding huge, close-in planets because their gravitational signals would just blur together.
“Transits and microlensing are complementary because they each reveal a category of planet the other may not be able to detect,” Dragomir said. “And they offer different details. Transits give us the size of a planet, and in concert with other methods we can determine its mass and density. Microlensing gives us masses and orbital distances for planets we’d otherwise never see.”
This graphic highlights the search areas of three planet-hunting missions: NASA’s upcoming Nancy Grace Roman Space Telescope, the retired Kepler Space Telescope, and NASA’s TESS (Transiting Exoplanet Survey Satellite). While TESS discovers transiting planets within a 150-light-year radius of Earth, it recently detected a planet about 40,000 light-years away (marked by the star symbol) via another method, called microlensing. NASA’s Goddard Space Flight Center
But microlensing observations are time-limited opportunities.
Microlensing events happen once and they’re gone — they don’t repeat. I like to joke that we’ll probably find the first Earth analog with microlensing, and then wave at it as it goes by because we’ll never see it again.Mallory Harris
Ph.D. candidate at the University of New Mexico
That makes detailed observations of microlensing planets tough. However, the method can serve as a powerful demographics tool that offers broad information about planetary populations.
“This is a bit like a preview of the microlensing NASA’s Nancy Grace Roman Space Telescope will do,” said Michael Fausnaugh, a professor at Texas Tech University in Lubbock and a co-author of the study. On track for launch on August 30, 2026, Roman will observe the center of the Milky Way galaxy for one of its core surveys, revealing an estimated 1,000 microlensing planets and around 100,000 transiting planets.
Roman will specifically target the heart of the galaxy because stars are packed so tightly together there, increasing the odds of seeing microlensing events. While that crowding would make many stars blend together in TESS’s larger pixels, TESS looks at nearly the whole sky, where stars are more spread out.
“Since TESS looks elsewhere in the galactic plane, it can naturally find microlensing planets in other parts of the galaxy, as demonstrated by this first microlensing planetary system,” Dragomir said. “That means it could help us study planets in regions with different conditions.”
That could have implications for the search for habitable worlds. The bustling galaxy center is rife with radiation from more frequent supernova explosions, which could sterilize planets. And gravitational encounters between crowded stars may disrupt planetary systems. Observations from TESS focus on a milder part of the galaxy.
“The key to Roman’s microlensing survey is its dense time coverage targeting the galactic bulge,” Fausnaugh said. “The TESS mission uniquely provides these rapid observations for stars in other parts of the galaxy, and pairing the two opens up prospects for understanding planet formation in a diverse population of stars. Since microlensing finds solar system-like planets, this offers a new chance to understand how planetary systems like our own vary in different regions of the galaxy.”
To learn more about the TESS mission, visit:
Media contact:
Claire Andreoli
NASA’s Goddard Space Flight Center, Greenbelt, Md.
301-286-1940
Ashley is the lead science writer for NASA’s Nancy Grace Roman Space Telescope.
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NASA’s TESS Mission Finds Planetary System in New Way
NASA’s Goddard Space Flight Center
For the first time, NASA’s TESS (Transiting Exoplanet Survey Satellite) mission has identified a planet orbiting a distant star thanks to ripples in space-time. Unlike the star-hugging transiting planets TESS regularly reveals, the newfound world is a super-Jupiter orbiting far from its host star.
“When TESS launched, no one expected it to ever be capable of finding this kind of planet,” said Diana Dragomir, a professor at the University of New Mexico in Albuquerque and co-author of a paper describing the results. At 1.6 times Jupiter’s mass and a similar orbital distance, it would be extremely unlikely to find such a planet via the primary detection method TESS was designed for. “The discovery implies that there are probably other so-called microlensing planets hiding in TESS’s data that we hadn’t previously thought to look for.”
This artist’s concept visualizes Gaia23bra b, the first microlensing planet orbiting a distant star found by NASA’s TESS (Transiting Exoplanet Survey Satellite). This super-Jupiter orbits an orange dwarf star at a distance similar to Jupiter’s distance from the Sun. NASA’s Goddard Space Flight CenterAstronomers found the first hint of the planet, called Gaia23bra b, in 2023 using ESA’s (European Space Agency) now-retired Gaia space telescope. Gaia’s alert system flagged a star that brightened — something that can happen when a foreground star passes in front of a more distant one and magnifies its light through gravitational microlensing.
Researchers later looked back through archived TESS data and found TESS had caught it too.
“Gaia’s observations were too sparse to pick up on the planet,” said Mallory Harris, a Ph.D. candidate at the University of New Mexico, who led the study. “The TESS spacecraft happened to be monitoring the same area of the sky during the event, and its denser time coverage showed extra features in the light curve caused by a planet.”
The team’s analysis, published July 1 in The Astrophysical Journal Letters, revealed that Gaia23bra b, which orbits an orange dwarf star that’s about 80 percent of the Sun’s mass, is nearly 40,000 light-years away from Earth, far exceeding TESS’s usual search radius of about 150 light-years.
Microlensing 101Out of more than 6,000 known exoplanets (worlds outside our solar system), about three-fourths were discovered via the transit method, TESS’s typical planet-hunting technique. Astronomers monitor hordes of stars, watching for ones that periodically dim as orbiting planets cross in front of them — an event called a transit.
This animation illustrates the concept of gravitational microlensing. When one star in the sky (shown in the center of the animation) appears to pass nearly in front of another (located in the dashed circle at the right) from our vantage point, the light rays of the background star become bent due to the warped space-time around the foreground star. This star acts like a virtual magnifying glass, amplifying the brightness of the background star and causing its position to appear to slightly shift. If the nearer star harbors a planetary system, then those planets can also act as lenses, each one producing a short deviation in the brightness of the source. When astronomers find planets this way, they can measure their mass and orbital distance from their host star. NASA’s Goddard Space Flight Center/CI LabMicrolensing has revealed less than 5% of known exoplanets. This light-bending phenomenon occurs when two stars align closely from our vantage point. Light from the more distant star curves as it travels through the warped space-time caused by the nearer star’s mass.
If the alignment is especially close, the nearer star acts like a cosmic lens, focusing and magnifying light from the background star. Planets orbiting the foreground star may also modify the distant star’s light, acting as their own tiny lenses. Astronomers see the effect as a spike in the star’s brightness.
The transit method is best at finding large planets orbiting very close to their host stars; large planets block the most starlight, while close-in planets are more likely to pass in front of the host star. These gargantuan, steamy worlds are fascinating to scientists, but astronomers want to find planets like those in our solar system, too. That’s microlensing’s specialty.
With microlensing, we can find smaller planets with greater orbital distances, including worlds in the habitable zone of their star and even farther away.Mallory harris
Ph.D. candidate at the University of New Mexico
Microlensing isn’t well suited to finding huge, close-in planets because their gravitational signals would just blur together.
“Transits and microlensing are complementary because they each reveal a category of planet the other may not be able to detect,” Dragomir said. “And they offer different details. Transits give us the size of a planet, and in concert with other methods we can determine its mass and density. Microlensing gives us masses and orbital distances for planets we’d otherwise never see.”
This graphic highlights the search areas of three planet-hunting missions: NASA’s upcoming Nancy Grace Roman Space Telescope, the retired Kepler Space Telescope, and NASA’s TESS (Transiting Exoplanet Survey Satellite). While TESS discovers transiting planets within a 150-light-year radius of Earth, it recently detected a planet about 40,000 light-years away (marked by the star symbol) via another method, called microlensing. NASA’s Goddard Space Flight CenterBut microlensing observations are time-limited opportunities.
Microlensing events happen once and they’re gone — they don’t repeat. I like to joke that we’ll probably find the first Earth analog with microlensing, and then wave at it as it goes by because we’ll never see it again.Mallory Harris
Ph.D. candidate at the University of New Mexico
That makes detailed observations of microlensing planets tough. However, the method can serve as a powerful demographics tool that offers broad information about planetary populations.
“This is a bit like a preview of the microlensing NASA’s Nancy Grace Roman Space Telescope will do,” said Michael Fausnaugh, a professor at Texas Tech University in Lubbock and a co-author of the study. On track for launch on August 30, 2026, Roman will observe the center of the Milky Way galaxy for one of its core surveys, revealing an estimated 1,000 microlensing planets and around 100,000 transiting planets.
Roman will specifically target the heart of the galaxy because stars are packed so tightly together there, increasing the odds of seeing microlensing events. While that crowding would make many stars blend together in TESS’s larger pixels, TESS looks at nearly the whole sky, where stars are more spread out.
“Since TESS looks elsewhere in the galactic plane, it can naturally find microlensing planets in other parts of the galaxy, as demonstrated by this first microlensing planetary system,” Dragomir said. “That means it could help us study planets in regions with different conditions.”
That could have implications for the search for habitable worlds. The bustling galaxy center is rife with radiation from more frequent supernova explosions, which could sterilize planets. And gravitational encounters between crowded stars may disrupt planetary systems. Observations from TESS focus on a milder part of the galaxy.
“The key to Roman’s microlensing survey is its dense time coverage targeting the galactic bulge,” Fausnaugh said. “The TESS mission uniquely provides these rapid observations for stars in other parts of the galaxy, and pairing the two opens up prospects for understanding planet formation in a diverse population of stars. Since microlensing finds solar system-like planets, this offers a new chance to understand how planetary systems like our own vary in different regions of the galaxy.”
To learn more about the TESS mission, visit:
Media contact:
Claire Andreoli
NASA’s Goddard Space Flight Center, Greenbelt, Md.
301-286-1940
Ashley is the lead science writer for NASA’s Nancy Grace Roman Space Telescope.
Share Details Last Updated Jul 01, 2026 Editor Ashley Balzer Contact Ashley Balzer ashley.m.balzer@nasa.gov Location Goddard Space Flight Center Related Terms Explore More 9 min read Citizen Scientists Spot Jupiter-like Planet in NASA TESS DataArticle
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Article
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At the heart of our own galaxy, there is a dense thicket of stars with…
Article
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NASA’s Nancy Grace Roman Space Telescope will provide one of the deepest-ever views into the…
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The best new science-fiction novels published in July 2026
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