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Alien life on nearby 'super Earth' much likelier than we thought, study claims

A hefty "super Earth" lurking in one of the closest star systems to our planet may be much better suited to supporting extraterrestrial life than scientists initially thought, a new study suggests. The alien world's relative proximity to Earth, and the nature of its home star, make it a prime candidate for follow-up observations, researchers say.

The exoplanet, dubbed GJ 3378b, was discovered in 2024 and orbits a red dwarf star around 25 light-years from our planet. The alien world circles its star every 21.5 days at a distance around 10 times closer than Earth orbits the sun, which would make it completely inhospitable in our solar system. But because the red dwarf emits around 90% less radiation than the sun does, GJ 3378b is slap bang in the middle of this star system’s "habitable zone," where liquid water could exist on the exoplanet's surface.

Researchers initially thought that GJ 3378b was around five times more massive than Earth. If the planet is rocky like ours, it would qualify as a "super Earth" — often considered the best candidates for sustaining extraterrestrial life. However, it was hard to tell if this world had a solid surface or was actually a mini gas giant. And even if it was rocky, its immense size would probably mean that its atmospheric pressure would be crushing, making it less likely to harbor life.

But in a new study, published June 30 in The Astrophysical Journal, researchers recalculated the exoplanet's size, using the Habitable-zone Planet Finder instrument attached to the Hobby-Eberly Telescope at the McDonald Observatory in Texas. This device measures subtle wobbles in the host star, caused by the gravitational tug of orbiting planets, and can be used to calculate the planet’s mass and trajectory.

This revealed that GJ 3378b is actually only 2.3 times more massive than Earth, which almost guarantees it is a rocky world and means it could have an atmosphere with a similar pressure to our own, raising the chances that extraterrestrial lifeforms could thrive there.

An artist's illustration of an exoplanet in space

The newly constrained size of GJ 3378b makes it much more likely that the exoplanet has an atmosphere similar to Earth's. But more research is needed to confirm if it even has an atmosphere. (Image credit: NASA/Eyes on Exoplanets viewer)

While researchers have found several other exoplanets that could harbor life, the fact that GJ 3378b is so close to us makes it particularly intriguing, as it will be easier to confirm whether it is truly habitable.

"This one’s exciting," study first author Paul Robertson, an astronomer at the University of California, Irvine, said in a statement. "25 light-years sounds like a long way, but the Milky Way is about 100,000 light-years across, so in that respect it’s our next-door neighbor."

Before we get too carried away, there is still no evidence that GJ 3378b has an atmosphere or liquid water. Its proximity to its home star may mean that any atmosphere it once had was stripped away by stellar winds, similar to how solar radiation likely stripped Mars of its atmosphere and ancient oceans.

Therefore, more observations are needed. But if an atmosphere is detected, GJ 3378b would likely jump to near the front of the queue of exoplanets that researchers want to study further.

"If a planet in the habitable zone has a proper atmosphere, we can justify further research looking for biosignatures, liquid water or other signs of life," study co-author Gogod James, an undergraduate student at UC Irvine, said in the statement.

The fact that GJ 3378b orbits a red dwarf also makes it more appealing for future study because this is the most common star type in the Milky Way, so experts are keen to learn more about these stars' planetary systems and potential to nurture life.

"About 70% of stars in our galaxy are red dwarfs, so they represent the standard," study co-author Michael Endl, an astronomer at the McDonald Observatory and the University of Texas at Austin, said in another statement. "It’s really important that we understand the planet population around these stars."

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This 'improbable' exoplanet system is so wonky because of a weird object within

Using NASA's exoplanet-hunting spacecraft TESS (Transiting Exoplanet Survey Satellite), scientists have discovered a planetary system that scientists are calling "improbable." It could change how we think about the mechanisms behind planet formation.

The reason for the unusual arrangement of this planetary system is a failed star or brown dwarf designated TOI-201 c. Objects like this get the slightly unfair nickname of "failed stars" because, despite forming from a collapsing cloud of gas and dust like other stars, they fail to gather enough mass to trigger nuclear fusion of hydrogen to helium in their cores. Brown dwarfs have masses between 13 and 80 times that of Jupiter, or 0.013 to 0.08 the mass of the sun. That puts them right between the most massive planets and the smallest stars.

TOI-201 c is on a highly elliptical orbit, taking 2,881 days to orbit its star, which has resulted in planets including a super-Earth named TOI-201 d and a warm Jupiter named TOI-201 b, forming in a narrow zone within its orbit, something that isn't just new to astronomers; it is completely unexpected based on planetary formation models.

The 5.8-day orbit of TOI-201 d and the 53-day orbit of TOI-201 b are both perfectly aligned with the orbit of the brown dwarf. The brown dwarf creates gravitational instability at distances equivalent to the distance between Mars and the sun, but this didn't prevent planets from forming in the system.

"This discovery provides a crucial insight into how planets form even around massive, eccentric objects," team member and INAF researcher Aldo Bonomo said in an emailed statement.

The system challenges the idea that gas giant planets form at distances equivalent to 2 to 3 times the distance between Earth and the sun in the disks of gas and dust that surround stars during their infancy.

"The presence of the brown dwarf on such an elliptical orbit forced the planets to form and survive by occupying the innermost and hottest edges of the primordial disk," team member Luca Naponiello of the National Institute for Astrophysics (INAF) said in the statement. "Furthermore, the data show that during the close approach of the brown dwarf, the warm Jupiter undergoes strong and sudden variations in its transit timing, bearing witness to an intense and vigorous dynamic interaction currently underway between the two giants."

The system was discovered by TESS using a rare mono-transit event, which describes a planetary body making one crossing of the face of its star, causing a dip in starlight. This was followed by an observing campaign conducted from the ground.

It is extremely rare to discover objects like TOI-201 c with such long and eccentric orbital periods using transits they make of their parent star. This brown dwarf is the first one of these objects to have its mass confirmed, making it an important step forward in astronomy.

"It [TOI-201c] is the transiting object with the longest orbital period for which the mass is known," Naponiello said.

The team's results were published on Wednesday (June 17) in the journal Nature.

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James Webb Space Telescope finds a salty surprise on famous 'Pink Planet'

Using the James Webb Space Telescope, astronomers have discovered that the well-known "Pink Planet" harbors a salty surprise and an exotic atmospheric chemistry. The discovery marks an advancement in the study of cold objects beyond the solar system.

Initially discovered in 2013, GJ504b orbits a sun-like star located around 57 light-years from Earth. With a mass around 25 times that of Jupiter, this Pink Planet may not be a planet at all despite its moniker. It may instead be a brown dwarf, a failed star that formed like a star but was unable to gather enough mass to achieve the nuclear fusion of hydrogen to helium in its core. Thus, astronomers refer to it as a "planetary-mass companion," which means a planet-size object orbiting a parent star.

GJ504b remains one of the coldest planetary-mass companions discovered using ground-based telescopes, with a temperature of around 550 degrees Fahrenheit (290 degrees Celsius). Although, that still makes it hot enough to bake bread. Now, James Webb Space Telescope (JWST) data reveals it has a key ingredient for bread making too: salt located in its atmospheric clouds, unlike anything astronomers have seen before.

"The Pink Planet is the coldest companion ever discovered using ground-based instruments," team leader Aneesh Baburaj of Northwestern University said in a statement. "Many teams all around the world performed follow-up observations to study its light, but it was too faint for ground-based instruments. That made it a perfect target for JWST.

"When we finally obtained its spectrum, it immediately looked interesting. But once we started digging deeper into the data, we realized it was not like anything we have analyzed before."

The Pink Planet is cold and old

The team studied this planetary companion by measuring its faint electromagnetic radiation emissions and filtering out the bright glare of its parent star.

They found the relative coolness of the Pink Planet is a result of the planet's age. Both gas giant planets and brown dwarfs are born blisteringly hot but cool off as they get older. This new research estimated that GJ504b is between 2.5 billion and 4 billion years old.

Breaking down light from the Pink Planet into individual wavelengths, the team was also able to determine its chemical composition. This is possible because elements absorb and emit light at characteristic wavelengths, meaning they leave "fingerprints" on light passing through their atmospheres.

"In the past, other astronomers observed the companion for an entire night with some of the biggest telescopes in the world to obtain a spectrum," Baburaj said. "And they could not see the object. With JWST, our entire observation took around two hours, and we were successful."

The JWST data revealed a rich cocktail of chemicals in the atmosphere of the Pink Planet that included water, carbon dioxide, methane, and ammonia. However, these observations didn't match modeling of the planetary companion's atmosphere until the team factored in something completely unexpected: clouds of salt deep in the atmosphere.

A depiction of a yellow-hexagon mirror attached to a long silver shield-shape object. This is the JWST. In the background, lots of stars across space. Toward the right in the background, glare from one star that is likely the sun.

An illustration of the JWST which has become a vital tool in the investigation of exoplanets and brown dwarfs. (Image credit: ESA)

"We ran simulations with clouds, and the results aligned with what we know about cold planets," Baburaj said. "We tried three different types of clouds, and salt clouds fit best. When we accounted for salt clouds, it subdued the signature of molecules hidden deeper in the companion’s atmosphere. Then, the results became physically possible.

"This is the first time we've found that salt clouds are critical to explaining the spectrum of an object. It's a good reminder to account for clouds in our models."

Though this mystery may be solved, there are still questions surrounding GJ504b that will only be solved with further investigation. The Pink Planet seems to be unusually rich in elements heavier than hydrogen and helium, which astronomers call metals. This means the team still can't pin down the origin of the Pink Planet; did it form like a planet, or like a star?

That means they aren't quite ready to determine if GJ504b is a gas giant planet or a brown dwarf... or should that be Pink Dwarf?

The team's research was published on Thursday (June 18) in The Astronomical Journal.

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Unusual Exoplanet Redefines the Concept of a Hot Jupiter

For nearly a decade, the hot Jupiter CoRoT-2 b has presented a profound mystery to astronomers: its atmospheric hot spot is inexplicably located opposite the position observed on all other exoplanets of its kind. This peculiar phenomenon challenges conventional wisdom about the nature of hot Jupiters and their atmospheric dynamics. Recent research led by Aurora Kesseli, a staff scientist at the NASA Exoplanet Science Institute (NExScI) housed within Caltech’s IPAC center, has shed new light on this enigma by leveraging advanced spectroscopic data obtained from the Very Large Telescope (VLT) at the European Southern Observatory. This breakthrough offers compelling evidence that CoRoT-2 b defies a fundamental assumption about hot Jupiters: it is not tidally locked to its host star.

Hot Jupiters are a fascinating class of exoplanets typified by their colossal size—often comparable to or exceeding that of Jupiter—and their blisteringly close orbits around host stars, sometimes completing a single revolution in mere days. Because of these properties, hot Jupiters serve as prime candidates for detailed atmospheric studies. Their proximity to the parent star means they receive intense irradiation, significantly influencing their atmospheric dynamics, radiative properties, and chemical compositions. This environment makes them critical laboratories for testing and refining planetary formation, evolution, and climate models.

The accepted paradigm for hot Jupiter atmospheres is predicated on tidal locking, whereby the planet’s rotation period synchronizes with its orbit, causing one hemisphere to perpetually face the star, exposed to relentless stellar radiation, while the opposite side remains cloaked in darkness. This lock is thought to occur rapidly due to strong gravitational interactions between the planet and its star. The perpetual dayside is expected to feature a dominant hot spot slightly offset towards the direction of planetary rotation and orbital motion, driven by atmospheric super-rotation. This consistent pattern is observed across many studied hot Jupiters, reinforcing tidal locking as a foundational concept within exoplanetary atmospheric science.

However, CoRoT-2 b stands out starkly against this backdrop. Discovered in 2007 and studied extensively since, this hot Jupiter’s hottest atmospheric region is displaced not ahead of but behind the substellar point—the point on the planet directly facing its star—opposite to the behavior seen in counterparts. Initial hypotheses proposed to explain this anomaly included obscuring cloud layers, magnetic field-driven atmospheric dynamics complicating wind patterns, or a rotation period differing from the orbital period. Previous work by Lisa Dang, a collaborator and professor at the University of Waterloo, outlined these potential explanations based on early observational data.

Aurora Kesseli and her team recently applied phase-resolved emission spectroscopy using the CRIRES+ instrument on the VLT, capturing the planet’s atmosphere in unprecedented detail across different orbital phases. This method enables tracing variations in emitted light corresponding to temperature and wind structures dynamically as the planet orbits. The data conclusively pointed toward the third hypothesis: CoRoT-2 b exhibits a rotation rate slower than its orbital period, meaning it is not synchronized tidally. Specifically, one full rotation of CoRoT-2 b lasts approximately three Earth days, while its orbital period is about 1.5 days. This differential implies that by the time the planet completes a single axial spin, it has circumnavigated its host star twice.

This non-synchronous rotation leads to a decoupling of the traditional tidally locked pattern of day-night heating contrasts, fundamentally altering how atmospheric circulation redistributes energy. Without tidal locking, the expected eastward-shifted hot spot is replaced by a distinct thermal signature resulting from slower planetary spin interacting with intense stellar irradiation. The discovery challenges standard assumptions embedded in many exoplanet climate models that universally prescribe tidal locking for hot Jupiters, suggesting a more nuanced picture with rotational diversity.

Understanding the rotational state of exoplanets like CoRoT-2 b carries broader implications, especially in the context of habitability studies. Many terrestrial exoplanets orbit M dwarfs, cool stars constituting roughly 70% of the stellar population in the Milky Way. These stars have habitable zones—regions where liquid water can persist on planetary surfaces—so close that tidal locking is highly probable within relatively short stellar lifetimes. Since rotation influences temperature gradients, weather systems, and atmospheric retention, a tidally locked terrestrial exoplanet’s climate could differ drastically from one with asynchronous rotation. Hence, unraveling CoRoT-2 b’s rotation contributes to refining the models employed for predicting environments on potentially habitable worlds in tight orbits.

While the revelation of CoRoT-2 b’s slow rotation solves a significant piece of the puzzle, it simultaneously opens further questions. The mechanisms driving this atypical rotational state in a planet where tidal forces should dominate remain elusive. Possible contributors might include magnetic torques, differential interior structures, or recent dynamical interactions within its planetary system that disturbed its spin. Future observations, especially with upcoming flagship observatories like the James Webb Space Telescope, the Habitable Worlds Observatory, and the ground-based Extremely Large Telescope, promise to provide deeper insight into these processes by offering higher precision data across broader wavelength ranges.

Hot Jupiters continue to act as vanguards in exoplanetary science. They are currently the best-understood and most accessible class of exoplanets for atmospheric characterization, enabling astronomers to test and recalibrate models of atmospheric physics, chemistry, and dynamics. The case of CoRoT-2 b exemplifies how nature’s variability often defies simplified expectations, compelling constant refinement of theories and models. These advances do not merely enhance comprehension of gas giants but ripple outward to shape understanding of all planetary atmospheres, including those bearing life.

Kesseli underscores the excitement of probing “weird” exceptions within the exoplanet census, emphasizing that such outliers drive scientific progress. As instrumentation improves and more extensive surveys unfold, the taxonomy of exoplanetary rotation states, atmospheric dynamics, and climate regimes will grow richer. This improved framework will essentialize our broader quest to understand planet formation, stellar influences, and potential biosignatures on distant worlds. CoRoT-2 b’s defiance of tidal locking invites the scientific community to remain alert to unexpected phenomena lurking in exoplanet atmospheres.

In summation, the unraveling of CoRoT-2 b’s anomalous atmospheric hot spot through rigorous spectroscopic measurements marks a milestone in exoplanet research. It dispels the notion of universal tidal locking among hot Jupiters and reveals a more intricate rotational behavior impacting atmospheric properties. The ongoing inquiry into the cause of this slowed rotation will propel future efforts to decipher planetary spins, magnetic interactions, and orbital dynamics across a diverse planetary population. These insights will deepen our grasp of planetary physics and help guide the search for habitable environments beyond our solar system.

Subject of Research: Atmospheric dynamics and rotational state of the hot Jupiter CoRoT-2 b
Article Title: Unraveling the Mystery of the Peculiar and Young Hot Jupiter CoRoT-2b II: Phase Resolved Emission Spectroscopy with VLT/CRIRES+ and Gemini-S/IGRINS
News Publication Date: June 16, 2026
Web References: IPAC News, NExScI at Caltech, University of Waterloo Newsroom
References: Kesseli et al., submitted to The Astronomical Journal
Image Credits: Keith Miller (Caltech/IPAC – SELab)

Keywords: hot Jupiter, CoRoT-2 b, tidal locking, exoplanet atmospheres, phase-resolved spectroscopy, planetary rotation, atmospheric dynamics, VLT/CRIRES+, exoplanet climate models, M dwarf habitability, rotational decoupling, spectroscopic observations

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NASA’s Webb Catches Exoplanet Getting Roasted

 
4 Min Read

NASA’s Webb Catches Exoplanet Getting Roasted

Illustration of a planet and a star, labeled artist’s concept at the bottom left. The planet fills more than a quarter of the image to the upper right, with the bright star to its lower left. The planet is white hot on the star side, fading to yellow that mixes with swirls of bright red across its middle, and eventually fading to black on the side most distant from the star. Distant stars dot the background of space, which is black near the edges of the frame.
This artist’s concept shows exoplanet HD 80606 b being “roasted” as its orbit approaches periastron, the point at which it is closest to its host star, which is similar to our Sun.
Credits:
Artwork: NASA, ESA, CSA, Joseph Olmsted (STScI)

4 min read

NASA’s Webb Catches Exoplanet Getting Roasted

One well-done gas giant, coming right up! That’s the latest from researchers analyzing NASA’s James Webb Space Telescope’s observations of HD 80606 b, an exoplanet four times the mass of Jupiter with an extremely elliptical orbit that sweeps close by its Sun-like star. The research team is presenting their study and preliminary findings Tuesday at the 248th meeting of the American Astronomical Society in Pasadena, California.

“Hot Jupiters are already considered some of the most extreme exoplanets we know of, but even among that population, HD 80606 b is one of the most extreme,” said Tiffany Kataria, the study’s principal investigator at NASA’s Jet Propulsion Laboratory in Southern California. “We typically think of hot Jupiters as hot gas giants sitting right next to their stars, but this planet’s highly eccentric orbit creates a completely different beast.”

As the planet plunges close to its star, Webb shows its temperature skyrockets by 1,100 degrees Fahrenheit. Previous studies have shown that radical temperature swings can cause an exoplanet’s chemistry and clouds to change in real time. According to the research team, the dynamic conditions of HD 80606 b make the planet an ideal target to observe these changes with Webb’s powerful instruments.

Image: Artist’s concept exoplanet HD 80606 b

Illustration of a planet and a star, labeled artistu2019s concept at the bottom left. The planet fills more than a quarter of the image to the upper right, with the bright star to its lower left. The planet is white hot on the star side, fading to yellow that mixes with swirls of bright red across its middle, and eventually fading to black on the side most distant from the star. Distant stars dot the background of space, which is black near the edges of the frame.
This artist’s concept shows exoplanet HD 80606 b being “roasted” as its orbit approaches periastron, the point at which it is closest to its host star, which is similar to our Sun.
Artwork: NASA, ESA, CSA, Joseph Olmsted (STScI)

“Observing a planet like HD 80606 b is actually very efficient because its unusual orbit, with the corresponding swings in temperature and chemical composition, allow us to gather data under varying conditions in just hours and apply those findings to other hot Jupiters or more conventional exoplanets,” said Laura C. Mayorga, co-investigator on the study and an exoplanet astronomer at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland.

Measurements of temperature and chemical composition were done with spectroscopy, a technique scientists use to break light into its component colors to reveal information about the composition, temperature, motion, and physical properties of objects in space. The team used Webb’s MIRI (Mid-Infrared Instrument) for an extended observation of HD 80606 b before, during, and after its periastron, or closest pass by its star. During periastron, the planet also passed behind the star from Webb’s perspective in what’s known as a secondary eclipse. The observation was years in the planning, as scheduling the time to catch the planet at this point was complex given its extremely elliptical 111-day orbit, and Webb’s own restrictions on where it can look during specific times of the year, based on Earth’s position in orbit around the Sun.

Researchers say they have only begun to peel back the layers of an incredibly rich dataset, but they can clearly see a dramatic shift in the exoplanet’s temperature. “Webb has shown that the planet’s increase in temperature was even more extreme than we anticipated based on Spitzer data,” said Kataria.

In fact, the planet had already been dubbed the “roasted exoplanet” and even got its own poster in NASA’s popular series. NASA’s now-retired Spitzer Space Telescope laid the groundwork of infrared observations of HD 80606 b, showing that more detailed spectroscopic data from Webb would be especially compelling.

“Spitzer did amazing work on this exoplanet, and now Webb is building on that legacy by enabling us to drill down to distinguish specific chemical signatures like methane and carbon dioxide, which is just amazing progress,” said Ryan Challener, co-author and research associate at the Cornell Center for Astrophysics and Planetary Science. “There’s so much to learn from this one dataset here — we really are just getting started deciphering what Webb has to tell us.”

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).

For more information on Webb, visit:

science.nasa.gov/webb

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

Illustration of a planet and a star, labeled artistu2019s concept at the bottom left. The planet fills more than a quarter of the image to the upper right, with the bright star to its lower left. The planet is white hot on the star side, fading to yellow that mixes with swirls of bright red across its middle, and eventually fading to black on the side most distant from the star. Distant stars dot the background of space, which is black near the edges of the frame.

HD 80606 b (Artist’s Concept)

This artist’s concept shows exoplanet HD 80606 b being “roasted” as its orbit approaches periastron, the point at which it is closest to its host star, which is similar to our Sun.

Related Links

Este Artículo en Español – “Telescopio Webb de la NASA Detecta un Exoplaneto Asandose”

Read:  Webb’s Impact on Exoplanet Research

Watch:  How to Study Exoplanets: Webb and Challenges

Explore:  Eyes on Exoplanets

Print: The Roasted Exoplanet Poster

More Webb: News | Images | Science | Home Page


Share

Details

Last Updated
Jun 17, 2026
Contact
Media

Laura Betz
NASA’s Goddard Space Flight Center
Greenbelt, Maryland
laura.e.betz@nasa.gov

Leah Ramsay
Space Telescope Science Institute
Baltimore, Maryland

Hannah Braun
Space Telescope Science Institute
Baltimore, Maryland

  •  

NASA’s Webb Catches Exoplanet Getting Roasted

 
4 Min Read

NASA’s Webb Catches Exoplanet Getting Roasted

Illustration of a planet and a star, labeled artist’s concept at the bottom left. The planet fills more than a quarter of the image to the upper right, with the bright star to its lower left. The planet is white hot on the star side, fading to yellow that mixes with swirls of bright red across its middle, and eventually fading to black on the side most distant from the star. Distant stars dot the background of space, which is black near the edges of the frame.
This artist’s concept shows exoplanet HD 80606 b being “roasted” as its orbit approaches periastron, the point at which it is closest to its host star, which is similar to our Sun.
Credits: Artwork: NASA, ESA, CSA, Joseph Olmsted (STScI)

4 min read

NASA’s Webb Catches Exoplanet Getting Roasted

One well-done gas giant, coming right up! That’s the latest from researchers analyzing NASA’s James Webb Space Telescope’s observations of HD 80606 b, an exoplanet four times the mass of Jupiter with an extremely elliptical orbit that sweeps close by its Sun-like star. The research team is presenting their study and preliminary findings Tuesday at the 248th meeting of the American Astronomical Society in Pasadena, California.

“Hot Jupiters are already considered some of the most extreme exoplanets we know of, but even among that population, HD 80606 b is one of the most extreme,” said Tiffany Kataria, the study’s principal investigator at NASA’s Jet Propulsion Laboratory in Southern California. “We typically think of hot Jupiters as hot gas giants sitting right next to their stars, but this planet’s highly eccentric orbit creates a completely different beast.”

As the planet plunges close to its star, Webb shows its temperature skyrockets by 1,100 degrees Fahrenheit. Previous studies have shown that radical temperature swings can cause an exoplanet’s chemistry and clouds to change in real time. According to the research team, the dynamic conditions of HD 80606 b make the planet an ideal target to observe these changes with Webb’s powerful instruments.

Image: Artist’s concept exoplanet HD 80606 b

Illustration of a planet and a star, labeled artistu2019s concept at the bottom left. The planet fills more than a quarter of the image to the upper right, with the bright star to its lower left. The planet is white hot on the star side, fading to yellow that mixes with swirls of bright red across its middle, and eventually fading to black on the side most distant from the star. Distant stars dot the background of space, which is black near the edges of the frame.
This artist’s concept shows exoplanet HD 80606 b being “roasted” as its orbit approaches periastron, the point at which it is closest to its host star, which is similar to our Sun.
Artwork: NASA, ESA, CSA, Joseph Olmsted (STScI)

“Observing a planet like HD 80606 b is actually very efficient because its unusual orbit, with the corresponding swings in temperature and chemical composition, allow us to gather data under varying conditions in just hours and apply those findings to other hot Jupiters or more conventional exoplanets,” said Laura C. Mayorga, co-investigator on the study and an exoplanet astronomer at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland.

Measurements of temperature and chemical composition were done with spectroscopy, a technique scientists use to break light into its component colors to reveal information about the composition, temperature, motion, and physical properties of objects in space. The team used Webb’s MIRI (Mid-Infrared Instrument) for an extended observation of HD 80606 b before, during, and after its periastron, or closest pass by its star. During periastron, the planet also passed behind the star from Webb’s perspective in what’s known as a secondary eclipse. The observation was years in the planning, as scheduling the time to catch the planet at this point was complex given its extremely elliptical 111-day orbit, and Webb’s own restrictions on where it can look during specific times of the year, based on Earth’s position in orbit around the Sun.

Researchers say they have only begun to peel back the layers of an incredibly rich dataset, but they can clearly see a dramatic shift in the exoplanet’s temperature. “Webb has shown that the planet’s increase in temperature was even more extreme than we anticipated based on Spitzer data,” said Kataria.

In fact, the planet had already been dubbed the “roasted exoplanet” and even got its own poster in NASA’s popular series. NASA’s now-retired Spitzer Space Telescope laid the groundwork of infrared observations of HD 80606 b, showing that more detailed spectroscopic data from Webb would be especially compelling.

“Spitzer did amazing work on this exoplanet, and now Webb is building on that legacy by enabling us to drill down to distinguish specific chemical signatures like methane and carbon dioxide, which is just amazing progress,” said Ryan Challener, co-author and research associate at the Cornell Center for Astrophysics and Planetary Science. “There’s so much to learn from this one dataset here — we really are just getting started deciphering what Webb has to tell us.”

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).

For more information on Webb, visit:

science.nasa.gov/webb

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

Illustration of a planet and a star, labeled artistu2019s concept at the bottom left. The planet fills more than a quarter of the image to the upper right, with the bright star to its lower left. The planet is white hot on the star side, fading to yellow that mixes with swirls of bright red across its middle, and eventually fading to black on the side most distant from the star. Distant stars dot the background of space, which is black near the edges of the frame.

HD 80606 b (Artist’s Concept)

This artist’s concept shows exoplanet HD 80606 b being “roasted” as its orbit approaches periastron, the point at which it is closest to its host star, which is similar to our Sun.

Related Links

Este Artículo en Español – “Telescopio Webb de la NASA Detecta un Exoplaneto Asandose”

Read:  Webb’s Impact on Exoplanet Research

Watch:  How to Study Exoplanets: Webb and Challenges

Explore:  Eyes on Exoplanets

Print: The Roasted Exoplanet Poster

More Webb: News | Images | Science | Home Page

Share

Details

Last Updated
Jun 16, 2026
Contact
Media

Laura Betz
NASA’s Goddard Space Flight Center
Greenbelt, Maryland
laura.e.betz@nasa.gov

Leah Ramsay
Space Telescope Science Institute
Baltimore, Maryland

Hannah Braun
Space Telescope Science Institute
Baltimore, Maryland

The post NASA’s Webb Catches Exoplanet Getting Roasted appeared first on NASA Science.

  •  

Eyes on Exoplanets Tutorial

Eyes on Exoplanets Tutorial

Video tutorial showing how to use NASA’s 3D interactive tool “Eyes on Exoplanets.”
NASA/JPL-Caltech

Welcome to NASA’s Eyes on Exoplanets! Use this tutorial to start exploring worlds beyond our own. With this 3D interactive tool, you can visit all the stars beyond the Sun where we’ve found other planets, called exoplanets. 

Choose a star or exoplanet and see an artist’s concept of what it might look like. Spin it around to see its sun and planetary system. Learn how long a trip there from Earth would take at light speed — or by jet plane, or family car!

Study the real versions of planets and stars cited in your favorite science fiction. See which planets reside in habitable zones, where liquid water could exist on their surfaces. Or, search “Where We Explore,” stars that future space telescopes will target when looking for Earth-like planets. You can also choose your location on Earth and see what’s in the sky above you right now.

Select any of the stars shown to see how many planets have already been found there. Examine how those star systems compare to the layout of our solar system, or check the sizes of individual planets — are they as small as Earth, or as big as Jupiter? 

See all the different techniques we’ve used to confirm the 6,000+ exoplanets discovered so far — among the billions we believe exist in the galaxy — and the many observatories, on Earth and in space, that have detected them. You can also browse some of our favorite weird worlds, or destinations featured in our Exoplanet Travel Bureau.

Where will you explore?

Transcript

Welcome to NASA’s Eyes on Exoplanets. With this interactive tool, you can explore all of the stars beyond the Sun where we’ve discovered planets known as exoplanets. When you enter the site, the default is this view from space. You can start your exploration here. Or if you know of a specific star or exoplanet you want to visit, enter that in the search bar at upper right. 

You can also select View from Earth. Choose your location and see what’s in the sky above you right now. Click and drag to explore different parts of the sky. In the lower right corner, you can choose different display options. You can see the constellations, view only stars that are visible to the naked eye, or see the stars that are good places for future telescopes to search for planets like Earth. 

These future target stars are shown as filled-in circles. If you click the gear symbol and switch from the star symbol to the circled number, you will see how many exoplanets have already been found around the star shown. 

When you select a star, you have three different view options. Starting in System View, you will see the star and where planets are located around it. The shaded green area marks the habitable zone, the region around a star where a planet could have liquid water on the surface, a key to the search for life beyond Earth. You can also see how this system compares to our solar system by selecting that feature in the lower right. The star view will show a hypothetical view of what the star might look like. 

Click “Learn More” to see basic information about the star, including its history and pop-culture references. You can see how it compares to our Sun and solar system and what we found so far. Under “How to Detect a Planet in the System,” you can learn about the different ways to discover an exoplanet and see how many planets have been found with each technique, as well as the prospects for discovering more. Finally, the planet view allows you to explore each planet in the system. 

For each confirmed exoplanet, you’ll see an artist’s concept of what it might look like and see how it compares to other planets. Planets also have an option to learn more, where you can see how far away it is, how long it would take to get there, how it was discovered, and which observatory found it. 

To see other discoveries made by that observatory, click “Browse Destinations” in the upper right menu. There you can also find curated lists of featured discoveries and truly weird worlds. 

As you can see, there are so many worlds to discover. Where will you explore?

The post Eyes on Exoplanets Tutorial appeared first on NASA Science.

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Now That’s Metal: How to Spot Stars That Have Swallowed Their Planets

An illustration of an exoplanet about to be engulfed by its host star

Planets that get too close to their host stars are liable to be engulfed and consumed. New research explores how to identify stars that have had a planetary snack.

It’s Snack Time

Being a planet that closely orbits its star is dangerous, and various dynamical processes can draw a planet inward past the point of no return. When a planet vanishes beneath the surface of its host, it eventually disintegrates within the star, its atoms mixing into the blazing stellar soup.

This outcome is likely extremely common across the universe, and researchers have begun to see evidence for it: stars that appear to have absorbed angular momentum from their planets, white dwarfs with uncanny metals in their spectra, and stars with chemical abundances that don’t match those of their siblings. Now, in a recent publication led by Kaitlyn Lane (Vanderbilt University), researchers seek to find observational signatures of planetary engulfment of rocky exoplanets by main-sequence stars.

Modeling Engulfment

Lane’s team focused on main-sequence stars in the range of 0.5 to 1.4 solar masses, using one-dimensional analytical models to determine which of these stars will most readily display signs of having engulfed a planet. They simulated the stars as they consumed either an Earth-like planet or a super-Earth with the same composition as Earth but 15 times its mass.

illustration of a planet being engulfed by its star

Diagram showing a planet being engulfed by its star and beginning to disintegrate before migrating inward. The boundary between the star’s outer convective zone (CZ) and inner radiative zone is shown. Click to enlarge. [Lane et al. 2026]

At the onset of the model, the engulfment is set to begin, the planet placed tangent to the star’s surface. The planets sink down and orbit just barely within their stars for 1–10 years, their solid surfaces slowly beginning to evaporate.

After that relatively lengthy phase, the process proceeds rapidly: as the planet inches deeper into its star, the drag forces grow stronger and the planet’s demise accelerates, with the planet disintegrating over the course of hours. In the last phase, the planet makes its final plunge and is destroyed in a half hour.

Signs of Planets Past

Lane’s team found that the planets tended to be destroyed fully within the outer convective layer of their stars, except in the case of the most massive stars studied here. For more massive stars, the outer convective zone is shallower than it is for the less massive stars, allowing a chunk of each planet to survive the passage through the convective zone to reach the radiative zone below.

simulation results showing planets disintegrating within their host stars

The trajectories of three example cases, showing how the planet loses mass as it spirals inward. In the 1.4-solar-mass case, part of the planet survives to reach the radiative zone, but the shallowness of the star’s convective zone means that the disintegrated planetary material is easier to observe. Click to enlarge. [Lane et al. 2026]

What this translates to, for the purposes of identifying planet-eating stars from afar, is that stars near the top of the mass range studied — from 1.0 to 1.4 solar masses — make the best targets. This is because the tell-tale planetary metals are not overly diluted within the stars’ relatively small convective zones, making these elements easier to detect. In terms of specific metals, the authors found that aluminum, calcium, and vanadium are the best signposts of planetary engulfment, with lithium also making the list.

While the authors acknowledge that there’s more work to be done — they plan to investigate the impacts of planetary engulfment on stellar structure more closely, for example — this work represents an important foray into identifying targets for future studies of stars that have eaten their planets.

Citation

“Observable Metal Pollution in Main-Sequence Stars: Simulations of Rocky Planets Engulfed by Stars in the 0.5 to 1.4 M⊙ Range,” Kaitlyn T. Lane et al 2026 ApJ 1003 67. doi:10.3847/1538-4357/ae5b9a

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The First Starspot Spectrum Revealed by JWST

M-dwarf star with starspots

Editor’s Note: Astrobites is a graduate-student-run organization that digests astrophysical literature for undergraduate students. As part of the partnership between the AAS and astrobites, we occasionally repost astrobites content here at AAS Nova. We hope you enjoy this post from astrobites; the original can be viewed at astrobites.org.

Title: A Panchromatic JWST Spectrum of a Giant Starspot on the Fully Convective M Dwarf TOI-3884
Authors: C. A. Murray et al.
First Author’s Institution: University of Colorado Boulder
Status: Published in ApJ

We often picture stars as smooth, glowing spheres, as if they’ve been run through an Instagram filter. But real stars have spots: cooler, darker regions on a star’s surface caused by strong magnetic fields.

Annoyingly, these spots can seriously interfere with how we study exoplanet atmospheres.

How to Probe a Planetary Atmosphere

Planetary atmospheres are often probed through transmission spectroscopy. When a planet transits its star, some starlight passes through the planet’s atmosphere before reaching us. We can distinguish the light that has passed through the planet’s atmosphere by comparing the star’s light in transit versus out of transit. In doing so, we can isolate the atmospheric spectrum and look for absorption features of species like water or oxygen.

Easy, right?

How Starspots Get in the Way

Things get more complicated once we stop thinking of the star as if it’s been smoothed out by an Instagram filter. Starspots are cooler than the surrounding stellar surface, which means they emit a different spectrum. They are also constantly changing: new spots can form, old ones can disappear, and the star’s rotation carries them in and out of view. This changes things.

First of all, your star’s spectrum changes over time, which could mean that the star’s spectrum out of transit is not the same as the star’s spectrum during transit. On the other hand, the planet may transit across a starspot instead of a “normal” stellar region. In this case, the light we measure during the transit is affected by the spot, and it is no longer accurate to directly compare it with the overall stellar light outside the transit.

Ultimately, absorption features that we thought were from the planetary atmosphere could actually be coming from starspot contamination instead.

Starspot Models: Our Solution?

To deal with this, astronomers build starspot models, where they vary the spots in terms of the following:

  • The surface covering fraction: this parameter tells us how much of the stellar surface is covered in spots
  • The temperature contrast: this parameter tells us how much cooler (in ratio) the spot is compared to the rest of the stellar surface, and by proxy how much dimmer

These models are promising, but how do we know that we have chosen the right parameters?

A Unique Laboratory: TOI-3884

The TOI-3884 system is a unique laboratory for testing our starspot models. As seen in Figure 1, it has very convenient starspot geometry, with a large starspot located close to its pole. On top of that, we observe this star almost completely pole-on, which means that we always see this starspot, no matter how much the star rotates. To top this all off, the star hosts a close-in planet, which orbits the star from pole to pole.

Illustration of the TOI-3884 system

Figure 1: Illustration of the TOI-3884 system. The pole (and rotation axis) of the star is indicated with a black “x,” indicating that we see the star almost pole-on. The polar starspot is indicated in grey, and the transiting planet TOI-3884b is indicated in black. Different dates are shown, illustrating how the system evolves over the span of a few weeks. [Adapted from Mori et al. 2025]

The planet transits the star, and as it does so, it always passes over the polar starspot. This gives us a rare opportunity to probe the spectrum of a starspot. Similar to how we can use normal in/out of transit observations to probe a planetary atmosphere, we can now compare the observations during/after a “starspot transit” to probe the starspot region. Today’s authors do exactly this using six different transit observations from JWST.

So… How Good Are Our Models?

From the JWST observations, the authors extract a starspot spectrum for the first time. Figure 2 shows this as the spot contrast (how much dimmer the spot is than the surrounding stellar surface) plotted across different wavelengths. To see how well our models are doing, they compare this observed spectrum to two commonly used starspot models. The difference between the data and the models (the residual) is plotted in the lower panel.

spectrum of TOI-3884’s starspot.

Figure 2: The spectrum of TOI-3884’s starspot. The y-axis in the upper panel, the spot contrast, indicates how much dimmer the starspot is compared to the “normal” stellar surface. Different observations taken with JWST are indicated in different colored crosses, and other previous observations are overplotted in various other shapes. Model starspot spectra are shown in dashed or dotted black lines. The residuals between the model spectra and the JWST observations are shown in the bottom panel. [Adapted from Murray et al. 2026]

At wavelengths longer than about 1 micron, in the near-infrared regime, things look good! The residuals stay small, meaning the models do a solid job reproducing the observations. But move left into shorter wavelengths, in the optical regime, and the agreement quickly falls apart. The residuals grow, and it becomes clear that the models are missing something.

There’s still work to be done before we can confidently probe planetary atmospheres at optical wavelengths without worrying about stellar contamination, and this observed starspot spectrum provides a unique benchmark to test future starspot models. For now, the near-infrared remains a safer and more reliable window for planet atmosphere studies.

Original astrobite edited by Natalie Price.

About the author, Elise Koo:

I’m a PhD student at the University of Amsterdam, working to detect magnetic interactions between stars and their planets using radio and spectroscopic observations. Outside of research, I like to try out a variety of sports.

The post The First Starspot Spectrum Revealed by JWST appeared first on AAS Nova.

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Life on the (Red) Edge

Earth in visible and near-infrared light

Editor’s Note: Astrobites is a graduate-student-run organization that digests astrophysical literature for undergraduate students. As part of the partnership between the AAS and astrobites, we occasionally repost astrobites content here at AAS Nova. We hope you enjoy this post from astrobites; the original can be viewed at astrobites.org.

Title: Retrieving the Red Edge on Earth-Like Planets with Heterogeneous Clouds and Surfaces
Authors: Zachary Burr et al.
First Author’s Institution: Jet Propulsion Laboratory; ETH Zurich
Status: Published in ApJ

In the next 25 years, astronomers could find signs of life on other planets with the launch of the Habitable Worlds Observatory. Atmospheric signs of life, known as atmospheric biosignatures, are how astronomers currently search for life on other planets. Figure 1 shows examples of atmospheric biosignatures with pictures of each chemical’s origin on Earth. Before E.T. can phone home, though, we have to understand what chemicals make up a planet’s atmosphere. To do this, astronomers can use spectroscopy to observe a planet’s atmosphere in different wavelengths and measure the types and quantities of chemicals present.

biosignatures in Earth's atmosphere

Figure 1: Atmospheric biosignatures present in Earth’s atmosphere. More abundant biosignatures include oxygen and ozone (byproducts of photosynthesis in plants and bacteria) and nitrous oxide (byproduct of bacteria that don’t need oxygen to survive). Less abundant biosignatures include isoprene (released from the breakdown of leaves that have fallen from trees) and sulfur gases (byproducts of cyanobacteria). [Kaz Gary]

There are many ways to observe the spectrum of a planet, but the one you’re probably most familiar with is transmission spectroscopy. You can learn more about transmission spectroscopy of exoplanet atmospheres and how to model transmission spectra with these bites: 1, 2, 3. However, all of the current techniques for exoplanet spectroscopy (including transmission spectroscopy) measure the star’s light and how the planet affects the star’s light. This means it’s heavily dependent on how we model the star’s light to indirectly observe the planet’s light. The only way to take the spectrum of a planet directly is with direct imaging: the technique that the future Habitable Worlds Observatory will use to find signs of life in planetary spectra.

But are atmospheric biosignatures the only way to tell if life exists on other planets? Short answer: absolutely not. Let’s take Earth as an example. If we imagine Earth as a directly imaged exoplanet and take spectra of the light it reflects, you’ll find that around near-infrared wavelengths (~700 nanometers or just past the red part of the visible light spectrum), the light reflected off of Earth increases sharply. This sharp increase is called the vegetation red edge and is caused by plant and ocean life on Earth’s surface as shown in Figure 2. This is made possible because chlorophyll (the thing that makes plants green) absorbs nearly all visible light but reflects near-infrared light. The vegetation red edge is an example of a surface biosignature. In today’s article, the authors determine if the vegetation red edge will be visible in spectra of Earth-like exoplanets!

Spectra of different sources of the vegetation red edge

Figure 2: Spectra of different sources of the vegetation red edge on Earth. The vegetation red edge is highlighted in gray where the spectra rapidly increase and then level off beyond the visible light part of the spectrum. Each color represents a different source with pictures of each source on the right-hand side of the plot. [O’Malley-James and Kaltenegger 2019]

Snapshots

Planets rotate; that’s how we have morning, noon, and night in 24 hours guaranteed. This means that different parts of the surface will be visible at different times when we take spectra. Sometimes, we may see more ocean than land, other times not. To determine if the vegetation red edge would be visible at all points in Earth’s day, the authors simulated nine different spectra of modern-day Earth representing nine snapshots of Earth’s rotation. Additionally, they also simulated a time-averaged spectrum that shows an entire Earth day in one snapshot without the time variability. These spectra are shown in Figure 3.

Spectra of a directly imaged modern-day Earth at nine different times in its rotation

Figure 3: Spectra of a directly imaged modern-day Earth at nine different times in its rotation. The y-axis is the ratio of the planet’s signal to the star’s signal and the x-axis is wavelength in microns. Each color represents a time in UTC and the black curve represents the time-averaged spectrum. [Burr et al. 2026]

The authors then run retrieval models on all nine spectra to see if the vegetation red edge would be detectable in each spectrum, including the time-averaged one. Retrieval models take into account characteristics of the planet that would affect how light moves through its atmosphere, such as the atmospheric chemicals present and the surface gravity. They then use this information to generate possible spectral models that could fit the data. The best-fit model allows astronomers to infer what the atmosphere is made of and properties of the planet such as surface gravity. Because we are looking at Earth in visible light, much of the light from the planet is reflected. Typically, models of Earth-like planets in visible wavelengths only include atmospheric albedo: the measure of how reflective a planet’s atmosphere is. However, surface biosignatures can also be reflective as shown by the vegetation red edge. The authors use this to their advantage and introduce a surface albedo into their model that changes with the amount of desert, vegetation, and ocean visible on Earth’s surface at that time. They then further divide the nine spectra into three different types based upon the visible surface: majority land; 50% land, 50% ocean; and majority ocean. Check out the article online to see a cool animation of the Earth rotating and how the spectrum looks different at each time!

Arr! There Be… Vegetables?

After running the models, the authors were able to detect a sharp increase in the surface albedo value in every spectrum, including the time-averaged one. This result is shown in Figure 4. The authors take this result one step further in order to validate that the vegetation red edge is actually a result of surface variation of vegetation. They re-run models on each of their spectra but instead include a constant surface albedo instead of a time-varying one. This resulted in incorrectly measured radii, chemicals, and surface gravity in nearly all of the models. Without the vegetation red edge and surface features, the models could not accurately determine if life was present on Earth.

Retrieved surface albedos for the nine time-varying spectra

Figure 4: Retrieved surface albedos for the nine time-varying spectra. The surface albedo is broken down into three different values (a₁, a₂, a₃). Each of these values represents a change in the surface albedo at different wavelengths (i.e., how reflective the surface is at three different wavelengths). The nine spectra were broken down by the amount of surface that was visible at that time and color-coded for each category. The time-averaged spectrum is shown in gray. Each category of spectra was able to retrieve an increase in reflected light from the surface at vegetation red edge wavelengths. The spectra that had the majority land visible have the biggest increase in the surface albedo. This makes sense since the amount of visible vegetation is the largest with majority-land planets. [Burr et al. 2026]

For the first time (to the author’s knowledge), the vegetation red edge has been shown to be a promising and observable biosignature in Earth-like atmospheres. This study has also laid the groundwork for future work on other surface biosignatures and their potential impact on spectra of habitable planets. Confirming signs of life in multiple different ways, both on the surface and in the atmosphere, will finally allow astronomers to say we are not alone in the universe. In fact, life likes to live on the (red) edge!

Original astrobite edited by Madison VanWyngarden.

About the author, Kaz Gary:

I am a fourth-year PhD candidate at The Ohio State University with a passion for planets. My current work focuses on modeling exoplanet observations for the Habitable Worlds Observatory and understanding planetary atmospheres. Outside of research, I help develop planetarium shows and love all forms of science communication. In my free time, I enjoy playing tabletop RPGs, painting, watching terrible reality TV, and hanging out with my pet hedgehog.

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Playing Pool with Planets

artist's impression of hot Jupiter exoplanets

Each Jupiter-size planet in the galaxy falls into one of three distinct categories: hot, warm, or cold. A new study suggests that despite the apparent differences between these populations, they may have all formed from the same underlying dynamical process: a game of pool played at planetary scales.

A Diversity of Jupiters

Though our solar system has only one Jupiter-size planet, elsewhere in the galaxy we have found three different species of these massive gas giants. Cold Jupiters closely resemble their namesake and orbit far from their host stars; hot Jupiters are the opposite and are found whipping around their stars on extremely close-in orbits. In between these are the warm Jupiters, which tend to orbit in the intermediate space between 0.1 and 1.0 au.

A rendering of a star with lots of spots and flares with a planet in the foreground.

An artist’s depiction of a hot Jupiter. These planets orbit extremely close to their host stars, but likely got to their locations by scattering inward from more distant orbits. [NASA/JPL-Caltech]

Though these three populations are defined by their orbital distances, they differ from each other in other ways as well. For example, hot Jupiters almost never have nearby companions; if there are any other planets circling the same star, they’re usually far-out cold Jupiters. They can also orbit in pretty much any direction, including opposite the direction of their star’s spin, and are usually on perfectly circular orbits. In contrast, warm Jupiters often have friends nearby, are much more aligned with their stars’ spins, and can have modest eccentricities.

Given these differences, it’s often thought that each of these populations arrived at its current location through different dynamical processes and that the history of the warm Jupiters is likely quite different from the history of the hot Jupiters. However, a new study led by Julia Esposito (Georgia Institute of Technology) has proposed an alternative view. Maybe these populations, though they appear different now, were all created by the same process: planet–planet scattering.

Virtual Planetary Billiards

A cartoon of Jupiters at different distances from the sun with labelled arrows flowing inwards and outwards from each.

A schematic showing where different planets ended up as a function of where they scattered from during their evolution. Click to enlarge. [Esposito et al. 2026]

Esposito and collaborators set up 1,500 virtual planetary systems with three massive planets each, then simulated how the orbits evolved before probing the final configurations. In crucial contrast to previous simulation studies, the team initialized their Jupiters across a range of different distances and included the effects of tides sapping energy from orbits of planets that got too close to their host stars.

At the end of the simulation, the team surveyed the digital carnage. Almost every virtual system ended with only two planets after either ejecting one away from the star or having two planets collide. But, remarkably, the remaining two-planet systems looked tantalizingly similar to what we actually observe, with a mix of hot, warm, and cold Jupiters. Even more exciting, the end populations were highly correlated to where the violent scattering event took place.

For example, the warm Jupiters were almost all produced by “warm scattering” simulations, where the scattering took place between 0.1 and 1.0 au. The planets that survived the simulations and ended up as warm Jupiters matched all of the properties of the real warm Jupiter population: they had nearby companions, were moderately eccentric, and were mostly aligned with their stars. The hot Jupiters, meanwhile, were almost all produced by “cold scattering” events where the flybys happened far from the star and resulted in one planet hurtling inwards. These also matched all of the observed properties of real hot Jupiters.

The researchers concluded that planet–planet scattering can produce both the warm and hot Jupiter populations so long as you let the planets scatter from a variety of different distances. This exciting theoretical insight, if correct, would mean that astronomers could stop searching for different pathways to create each population. Happily, this model also provides testable predictions, and the authors lay out how the theory could be supported or disproven with additional data. Through virtual experiments like these, astronomers continue to build up an understanding of how the wide range of planetary architectures observed across the galaxy came to be.

Citation

“Unified Formation Channel of Hot and Warm Jupiters via Planet–Planet Scattering,” Julia Esposito et al 2026 ApJL 1003 L3. doi:10.3847/2041-8213/ae61b0

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Hunting for Exomoons Around a Lonely Planet

illustration of an exoplanet and exomoon around a star

Editor’s Note: Astrobites is a graduate-student-run organization that digests astrophysical literature for undergraduate students. As part of the partnership between the AAS and astrobites, we occasionally repost astrobites content here at AAS Nova. We hope you enjoy this post from astrobites; the original can be viewed at astrobites.org.

Title: A Deep Search for Exomoons Around WISE 0855 with JWST
Authors: Mikayla J. Wilson et al.
First Author’s Institution: University of California, Santa Cruz
Status: Published in AJ

The “Moon”-umental Question

The solar system hosts hundreds of moons, ranging from volcanic worlds like Io around Jupiter, to icy objects like Enceladus around Saturn, to captured objects like Neptune’s retrograde moon Triton. Moons are essential to our model of how the solar system formed and also offer some of the best chances we have for finding life beyond Earth.

Astronomers also expect exomoons, or moons orbiting planets outside the solar system, to be abundant around other giant exoplanets. But how common are exomoons? How do they compare to the moons in our solar system?

In order to begin answering those questions, we must first detect an exomoon, which has proved difficult despite decades of searching by astronomers. Fortunately, JWST presents a new opportunity to uncover the exomoon population by looking at lonely free-floating planets as they drift through space.

Why Free-Floating Planets?

One proposed method for searching for exomoons is by looking for their transits in front of their host planets, characterized by the dips in brightness of the planet as the moon passes in front, blocking the planet’s light. Looking for exomoon transits around planets orbiting stars is quite difficult, as the bright starlight can easily drown out the small signals of exomoon transits. Free-floating planets solve this issue by removing the star entirely, increasing our sensitivity to such detections. (See this bite for a good review.)

The authors of today’s article directed the exomoon hunt towards the free-floating WISE J085510.83-071442.5 (or WISE 0855). It has the prestige of being the coldest known brown dwarf (250–285K) while also sitting at a relatively low mass (3–10 Jupiter masses). Notably, it is also one of our closest neighbors at a distance of only 7.4 light-years, making it ideal for high-precision observations despite its faintness. Even though brown dwarfs are technically distinct from planets, the authors opt to refer to companions around WISE 0855 as moons given WISE 0855’s “planetary-mass” status. (It’s complicated…)

Repurposing JWST Data… for Moons!

The JWST observations used in this study contain 11 hours of near-infrared (2.87–5.27 microns) time-series spectra originally intended to study water clouds and weather on WISE 0855. Time-series brightness monitoring can also be used for transit searches, which the authors take advantage of.

One complication is that WISE 0855 is variable, meaning its intrinsic brightness changes over time. Variability is likely driven by clouds and other dynamic processes within its atmosphere. So how do the authors distinguish between a passing moon and a turbulent atmosphere? The key idea is that variability is wavelength dependent, meaning that the brightness of WISE 0855 will fluctuate differently depending on the observed wavelength. In contrast, transits are “gray,” meaning that the same amount of light is blocked at all wavelengths, producing a consistent feature across the entire spectrum.

Finding Moons with Statistics!

The authors apply this idea and pick out two wavelength regions of WISE 0855’s spectrum that contain two distinct variability patterns, which should both contain an identical moon transit signal (if present). They then generate a light curve (how brightness changes over time) for these two regions (see Fig. 1).

WISE 0855 light curves

Figure 1: (A) Light curves from two selected wavelength regions of WISE 0855’s spectrum with injected transit signals. Also plotted is the best-fit Gaussian processes + transit model for the two light curves. (B) Light curve data after subtracting the Gaussian processes portion of the best-fit model, revealing the example injected transit signals. [Wilson et al. 2025]

To appropriately model the variability, the authors employ Gaussian processes, a flexible tool that can model complex, quasi-periodic signals like atmospheric variability. They compare fits from two types of models:
  • Gaussian processes–only model: Assumes that all observed variability is intrinsic to the planet itself
  • Gaussian processes + transit model: Includes a simple trapezoidal exomoon transit signal that is simultaneously fit in both light curves

Using Bayesian evidence (a measure of how well each model explains the data), they determined which model was favored. So, what do they find?

The Bad News and the Good News

Based on Bayesian evidence, the authors conclude that there are no statistically significant detections of exomoons in the data. The results suggest very weak evidence for a ~0.53-Earth-radius moon at a wide separation from WISE 0855 — an unlikely scenario given that transit probability decreases at greater separations (and therefore longer orbital periods).

Yet, the study goes further: What kinds of moons is JWST able to detect, if any? To answer this, the authors performed injection and recovery tests, where they injected artificial transit signals of varying depths (exomoon sizes) into the data and tested how well their models were able to recover them (results shown in Fig. 2). They find that JWST is capable of detecting 96% of transits with depths ≥0.5%, equivalent to a Titan-like moon. Smaller Io-like moons were also detectable more than half of the time. This means that if a Titan analog had actually transited during these observations, we would almost certainly have seen it!

plot of successful detections of injected transit signals

Figure 2: Results showing the number of successful detections for the transit injection and recovery tests. Fifty transit injections are done for transit depths of 1%, 0.5%, 0.4%, 0.3%, 0.2%, and 0.1%. The transit depths represent different exomoon sizes, with the shaded regions representing Io-like and Titan-like moons. [Wilson et al. 2025]

JWST will continue to gather more time-series data of free-floating planets, brown dwarfs, and directly imaged exoplanets, each providing a new opportunity to help us better understand the moon population outside of our solar system. We’re still waiting for the first confirmed exomoon, but when that transit finally happens, we know that JWST will be ready.

Original astrobite edited by Kelsie Taylor.

About the author, Jared Bull:

I am a 2nd-year PhD student at Johns Hopkins University. I study brown dwarf variability and am interested in using time-series observations to uncover dynamic processes within their atmospheres. In my free time I like to read, cook, and do astrophotography.

The post Hunting for Exomoons Around a Lonely Planet appeared first on AAS Nova.

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Characterizing the Atmosphere of Exoplanet WD 0806b with JWST

gas giant orbiting white dwarf

Orbiting a white dwarf, the exoplanet WD 0806b is the subject of a recent study using JWST to measure the atmospheric conditions governing the planet.

Directly Imaged Exoplanet WD 0806b

Most of the 6,000 and counting exoplanets discovered thus far have been detected due to their impacts on their host star — passing in front of the star and causing it to dim, or gravitationally tugging on the star and causing it to wobble. On rare occasions, though, astronomers have been able to catch the exoplanet itself through direct imaging. Directly imaged exoplanets offer key insights that cannot be obtained through indirect detection methods. Luminosity measurements and spectral emission features allow astronomers to more directly measure planet mass, radius, and composition otherwise inferred from the host star.

WD 0806b system

NIRCam image showing host star WD 0806 circled in orange and the location of exoplanet WD 0806b marked by the orange arrow. [Lew et al 2026]

Included in the about 90 distant planets that have posed for a picture is WD 0806b, a rare exoplanet companion trotting around a white dwarf at an orbital distance of 2,500 au (50 times the distance from the Sun to the Kuiper belt!). Originally discovered with the Spitzer Infrared Array Camera in 2011, WD 0806b is the second-coldest directly imaged exoplanet to date. With JWST’s high-precision photometric and spectroscopic capabilities, WD 0806b provides a unique opportunity to probe the atmospheric chemistry of cold giant planets and take steps toward understanding the co-evolution of white dwarfs and their surviving exoplanets.

WD 0806b’s Atmospheric Abundances from JWST

Aiming to characterize the physical properties and atmospheric composition of WD 0806b, Ben W.P. Lew (Bay Area Environmental Research Institute; NASA Ames Research Center) and collaborators used JWST’s Near-Infrared Camera (NIRCam) and Near-Infrared Spectrograph (NIRSpec) to obtain high-resolution imaging and spectroscopy of the exoplanet. Combining these observations, prior lower-resolution observations, and evolutionary planet models, the authors estimated the physical properties of WD 0806b including mass, radius, surface gravity, and effective temperature.

WD 0806b spectrum

NIRSpec spectrum of WD 0806b with best-fit model spectra overlaid. [Lew et al 2026]

From the derived physical properties, the authors modeled the NIRSpec spectrum to estimate molecular abundances and elemental abundance ratios in the atmosphere of WD 0806b. They obtained measurements of multiple molecules including carbon dioxide, carbon monoxide, and ammonia; these molecular abundances offer the opportunity to test chemical equilibrium and disequilibrium as well as eddy diffusion, or bulk mixing, in the planet’s atmosphere. The authors developed a novel chemical analysis framework to determine how bulk mixing varies with altitude in WD 0806b and reported the first observational evidence that mixing becomes weaker at higher altitudes in exoplanet atmospheres. This result points to the need for future studies exploring the impact of these chemical processes on spectra and photometry, which are essential to characterizing cold giant planets.

This study highlights how high-precision JWST data can reveal a rich collection of atmospheric conditions, chemical composition, and physical processes occurring in cold giant planets. With such a wide orbit from its host white dwarf, WD 0806b serves as an interesting case study for how giant planet composition may reflect the formation and evolutionary history of the overall system. Future observations of and comparisons to similarly cold giant planets will further uncover how atmospheric characterization may fit into our understanding of exoplanets and their histories.

Citation

“JWST Spectral Retrieval of Cold Directly Imaged Planet WD 0806b and the First Measurement of Altitude-dependent Kzz in Exoplanet Atmospheres,” Ben W.P. Lew et al 2026 AJ 171 227. doi:10.3847/1538-3881/ae4747

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Getting a Peek of Kitt Peak National Observatory

KPNO

After AAS 247 in Phoenix, Arizona, AAS Nova Editor Kerry Hensley and I had the chance to travel about 150 miles south for a tour of Kitt Peak National Observatory.

A Window into Kitt Peak

Located 60 miles southwest of Tucson, Kitt Peak National Observatory (KPNO) resides on a mountain top within the Tohono O’odham Nation reservation. Founded in 1958, Kitt Peak is home to nearly two dozen active telescopes ranging in wavelength coverage and scientific objectives. Ronald Proctor, Lori Allen, and Jacelle Ramon-Sauberan, all serving in crucial roles for the observatory, led our tour around the mountain.

Windows Center Lobby

The Windows On the Universe Center’s lobby exhibit displaying the Tohono O’odham language with words describing the land and astronomy. Jacelle Ramon-Sauberan, the Tohono O’odham Nation Education Liaison, is seen to the left. [KPNO/NOIRLab/NSF/AURA/R. Proctor; CC BY 4.0]

Our visit began in the new Windows on the Universe Center — the first science center inside of a telescope. Situated inside the retired McMath-Pierce Solar Telescope, the Windows Center takes visitors through exhibits exploring the universe, the telescope’s original control room, and the observatory’s connection to the Tohono O’odham Nation.

The center’s lobby introduced visitors to the beautiful land KPNO calls home. Working with Tohono O’odham linguists, Jacelle, the observatory’s Tohono O’odham Nation Education Liaison, curated the lobby exhibit that features the native language and the Nation’s connection to astronomy and the observatory. The science center serves as an educational resource and place of cultural exchange, expanding the relationship between the observatory and the Tohono O’odham Nation. 

Astronauts

Apollo astronauts in the control room of the McMath-Pierce Solar Telescope in 1964. [United States Geological Survey; CC BY 4.0]

After walking through an introduction to the universe exhibit, visitors enter the original control room of the telescope. Mirrors across the room’s ceiling focus the Sun’s light onto table screens where visitors can observe the Sun in real time without burning their eyeballs. In addition to observing the Sun, the solar telescope allowed astronauts in the 1960s to view a projection of the Moon’s surface and plan their landing site for the Apollo 11 mission. Visitors can stand in the same place and witness the instruments that made the moon landing possible.

At the end of the Windows Center is a Science On a Sphere Theater — a spherical display system that allows visitors to see planets, stars, moons, and even large-scale structures of the universe in 3D. Featuring multiple programs, the theater takes visitors through the universe and displays data collected right there on the mountain!

WIYN

The WIYN 3.5-meter telescope at sunset. [KPNO/NOIRLab/NSF/AURA/P. Marenfeld; CC BY 4.0]

A WIYN for Exoplanetary Science

Though not typically open to the public for tours, our next stop took us to the WIYN 3.5-meter telescope. This telescope is operated and owned by the WIYN Consortium, a partnership between the University of Wisconsin, Indiana University, NSF’s NOIRLab (National Optical-Infrared Astronomy Research Laboratory; formerly NOAO), Pennsylvania State University, and Princeton University. Operating since 1994 with a strong collection of instruments, WIYN has observed galaxies near and far, stars across their lifetimes, and exoplanets tugging on their host stars.

Lexi at WIYN

Me, Lexi Gault (AAS Media Fellow), in front of the WIYN 3.5-meter telescope. I have used WIYN’s SparsePak spectrograph to collect data for my dissertation research! [AAS Nova/Kerry Hensley]

WIYN’s newest instrument, NEID (pronounced “NOO-id”), has been advancing exoplanetary science since its first light in early 2020. Derived from the word meaning “to see” in the Tohono O’odham language, NEID is a high-resolution spectrograph that uses the radial velocity method to detect exoplanets. As a planet orbits its host star, its gravitational pull induces a wobble in the star, and NEID can detect these wobbles with unprecedented precision. This instrument allows astronomers to find exoplanets that were previously undetectable.

The partnership between public and private universities and a government institution was the first of its kind. Through this consortium, hundreds of undergraduate and graduate students have conducted research with WIYN, and the telescope’s suite of instruments have enabled early career astronomers to explore the universe both near and far.

Mysteries of Dark Energy at Mayall

We concluded our tour at the Mayall 4-meter Telescope, the tallest telescope dome on the mountain at a staggering 18 stories high. This iconic telescope saw first light in 1973, and at the time, was the second-largest (in diameter) telescope in the world. Originally built for wide-field optical and infrared studies of the universe, the Mayall has enabled decades of critical scientific research.

Mayall dome

The Mayall dome across the mountain as seen from inside the WIYN dome. [AAS Nova/Lexi Gault]

Mayall is now home to the Dark Energy Spectroscopic Instrument (DESI), the most powerful multi-object survey spectrograph in the world. The DESI survey measures the impact of dark energy on the expansion of the universe through creating the largest ever 3D map of the universe. Mapping the distances to hundreds of millions of galaxies, DESI has revolutionized cosmology and enabled groundbreaking research into the origins of the universe. 

From the telescope’s massive dome, to the busy DESI control room, to the gallery floor with a nearly 360 degree view of the surrounding desert, the Mayall offers visitors a unique glimpse into Kitt Peak’s history and its future. While WIYN is a hidden gem, the Mayall 4-meter Telescope is open to the public for tours daily, so you can experience the exciting era of research and discovery at KPNO. 

Visit Kitt Peak

Interested in getting a peek yourself? KPNO is open to the public daily with multiple tour types to choose from, including both daytime and nighttime visits! Plan your visit to Kitt Peak here.

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