Members Can Post Anonymously On This Site
Astronomers Measure Mass of Largest Dwarf Planet
-
Similar Topics
-
By European Space Agency
Registrations are now open for the European Space Agency’s Living Planet Symposium (LPS) – one of the largest Earth observation conferences in the world. The event will take place on 23–27 June 2025 in Vienna, Austria.
View the full article
-
By NASA
Explore This Section Webb News Latest News Latest Images Blog (offsite) Awards X (offsite – login reqd) Instagram (offsite – login reqd) Facebook (offsite- login reqd) Youtube (offsite) Overview About Who is James Webb? Fact Sheet Impacts+Benefits FAQ Science Overview and Goals Early Universe Galaxies Over Time Star Lifecycle Other Worlds Observatory Overview Launch Deployment Orbit Mirrors Sunshield Instrument: NIRCam Instrument: MIRI Instrument: NIRSpec Instrument: FGS/NIRISS Optical Telescope Element Backplane Spacecraft Bus Instrument Module Multimedia About Webb Images Images Videos What is Webb Observing? 3d Webb in 3d Solar System Podcasts Webb Image Sonifications Team International Team People Of Webb More For the Media For Scientists For Educators For Fun/Learning 6 Min Read NASA Webb’s Autopsy of Planet Swallowed by Star Yields Surprise
NASA’s James Webb Space Telescope’s observations of what is thought to be the first-ever recorded planetary engulfment event revealed a hot accretion disk surrounding the star, with an expanding cloud of cooler dust enveloping the scene. Webb also revealed that the star did not swell to swallow the planet, but the planet’s orbit actually slowly depreciated over time, as seen in this artist’s concept. Full illustration below. Credits:
NASA, ESA, CSA, R. Crawford (STScI) Observations from NASA’s James Webb Space Telescope have provided a surprising twist in the narrative surrounding what is believed to be the first star observed in the act of swallowing a planet. The new findings suggest that the star actually did not swell to envelop a planet as previously hypothesized. Instead, Webb’s observations show the planet’s orbit shrank over time, slowly bringing the planet closer to its demise until it was engulfed in full.
“Because this is such a novel event, we didn’t quite know what to expect when we decided to point this telescope in its direction,” said Ryan Lau, lead author of the new paper and astronomer at NSF NOIRLab (National Science Foundation National Optical-Infrared Astronomy Research Laboratory) in Tuscon, Arizona. “With its high-resolution look in the infrared, we are learning valuable insights about the final fates of planetary systems, possibly including our own.”
Two instruments aboard Webb conducted the post-mortem of the scene – Webb’s MIRI (Mid-Infrared Instrument) and NIRSpec (Near-Infrared Spectrograph). The researchers were able to come to their conclusion using a two-pronged investigative approach.
Image A: Planetary Engulfment Illustration
NASA’s James Webb Space Telescope’s observations of what is thought to be the first-ever recorded planetary engulfment event revealed a hot accretion disk surrounding the star, with an expanding cloud of cooler dust enveloping the scene. Webb also revealed that the star did not swell to swallow the planet, but the planet’s orbit actually slowly depreciated over time, as seen in this artist’s concept. NASA, ESA, CSA, R. Crawford (STScI) Constraining the How
The star at the center of this scene is located in the Milky Way galaxy about 12,000 light-years away from Earth.
The brightening event, formally called ZTF SLRN-2020, was originally spotted as a flash of optical light using the Zwicky Transient Facility at the Palomar Observatory in San Diego, California. Data from NASA’s NEOWISE (Near-Earth Object Wide-field Infrared Survey Explorer) showed the star actually brightened in the infrared a year before the optical light flash, hinting at the presence of dust. This initial 2023 investigation led researchers to believe that the star was more Sun-like, and had been in the process of aging into a red giant over hundreds of thousands of years, slowly expanding as it exhausted its hydrogen fuel.
However, Webb’s MIRI told a different story. With powerful sensitivity and spatial resolution, Webb was able to precisely measure the hidden emission from the star and its immediate surroundings, which lie in a very crowded region of space. The researchers found the star was not as bright as it should have been if it had evolved into a red giant, indicating there was no swelling to engulf the planet as once thought.
Reconstructing the Scene
Researchers suggest that, at one point, the planet was about Jupiter-sized, but orbited quite close to the star, even closer than Mercury’s orbit around our Sun. Over millions of years, the planet orbited closer and closer to the star, leading to the catastrophic consequence.
“The planet eventually started to graze the star’s atmosphere. Then it was a runaway process of falling in faster from that moment,” said team member Morgan MacLeod of the Harvard-Smithsonian Center for Astrophysics and the Massachusetts Institute of Technology in Cambridge, Massachusetts. “The planet, as it’s falling in, started to sort of smear around the star.”
In its final splashdown, the planet would have blasted gas away from the outer layers of the star. As it expanded and cooled off, the heavy elements in this gas condensed into cold dust over the next year.
Inspecting the Leftovers
While the researchers did expect an expanding cloud of cooler dust around the star, a look with the powerful NIRSpec revealed a hot circumstellar disk of molecular gas closer in. Furthermore, Webb’s high spectral resolution was able to detect certain molecules in this accretion disk, including carbon monoxide.
“With such a transformative telescope like Webb, it was hard for me to have any expectations of what we’d find in the immediate surroundings of the star,” said Colette Salyk of Vassar College in Poughkeepsie, New York, an exoplanet researcher and co-author on the new paper. “I will say, I could not have expected seeing what has the characteristics of a planet-forming region, even though planets are not forming here, in the aftermath of an engulfment.”
The ability to characterize this gas opens more questions for researchers about what actually happened once the planet was fully swallowed by the star.
“This is truly the precipice of studying these events. This is the only one we’ve observed in action, and this is the best detection of the aftermath after things have settled back down,” Lau said. “We hope this is just the start of our sample.”
These observations, taken under Guaranteed Time Observation program 1240, which was specifically designed to investigate a family of mysterious, sudden, infrared brightening events, were among the first Target of Opportunity programs performed by Webb. These types of study are reserved for events, like supernova explosions, that are expected to occur, but researchers don’t exactly know when or where. NASA’s space telescopes are part of a growing, international network that stands ready to witness these fleeting changes, to help us understand how the universe works.
Researchers expect to add to their sample and identify future events like this using the upcoming Vera C. Rubin Observatory and NASA’s Nancy Grace Roman Space Telescope, which will survey large areas of the sky repeatedly to look for changes over time.
The team’s findings appear today in The Astrophysical Journal.
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: https://science.nasa.gov/webb
Downloads
Click any image to open a larger version.
View/Download all image products at all resolutions for this article from the Space Telescope Science Institute.
View/Download the science paper from the The Astrophysical Journal.
Media Contacts
Laura Betz – laura.e.betz@nasa.gov
NASA’s Goddard Space Flight Center, Greenbelt, Md.
Hannah Braun – hbraun@stsci.edu
Space Telescope Science Institute, Baltimore, Md.
Related Information
Read more about Webb’s impact on exoplanet research
Video: How to Study Exoplanets
Learn more about exoplanets
More Webb News
More Webb Images
Webb Science Themes
Webb Mission Page
Related For Kids
What is the Webb Telescope?
SpacePlace for Kids
En Español
Ciencia de la NASA
NASA en español
Space Place para niños
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
Stars
Universe
Share
Details
Last Updated Apr 10, 2025 Editor Marty McCoy Contact Laura Betz laura.e.betz@nasa.gov Related Terms
James Webb Space Telescope (JWST) Astrophysics Exoplanets Goddard Space Flight Center Science & Research Stars The Milky Way The Universe View the full article
-
By NASA
In about 5 billion years, our Sun will run out of fuel and expand, possibly engulfing Earth. These end stages of a star’s life can be utterly beautiful – as is the case with this planetary nebula called the Helix Nebula. Astronomers study these objects by looking at all kinds of light.X-ray: NASA/CXC/SAO/Univ Mexico/S. Estrada-Dorado et al.; Ultraviolet: NASA/JPL; Optical: NASA/ESA/STScI (M. Meixner)/NRAO (T.A. Rector); Infrared: ESO/VISTA/J. Emerson; Image Processing: NASA/CXC/SAO/K. Arcand This image of the Helix Nebula, released on March 4, 2025, shows a potentially destructive white dwarf at the nebula’s center: this star may have destroyed a planet. This has never been seen before – and could explain a mysterious X-ray signal that astronomers have detected from the nebula for over 40 years.
This view combines X-rays from NASA’s Chandra X-ray Observatory (magenta), optical light data from NASA’s Hubble Space Telescope (orange, light blue), infrared data from the European Southern Observatory VISTA telescope (gold, dark blue), and ultraviolet data from GALEX (purple) of the Helix Nebula. Data from Chandra indicates that this white dwarf has destroyed a very closely orbiting planet.
Image credit: X-ray: NASA/CXC/SAO/Univ Mexico/S. Estrada-Dorado et al.; Ultraviolet: NASA/JPL; Optical: NASA/ESA/STScI (M. Meixner)/NRAO (T.A. Rector); Infrared: ESO/VISTA/J. Emerson; Image Processing: NASA/CXC/SAO/K. Arcand
View the full article
-
By NASA
Researchers analyzing pulverized rock onboard NASA’s Curiosity rover have found the largest organic compounds on the Red Planet to date. The finding, published Monday in the Proceedings of the National Academy of Sciences, suggests prebiotic chemistry may have advanced further on Mars than previously observed.
Scientists probed an existing rock sample inside Curiosity’s Sample Analysis at Mars (SAM) mini-lab and found the molecules decane, undecane, and dodecane. These compounds, which are made up of 10, 11, and 12 carbons, respectively, are thought to be the fragments of fatty acids that were preserved in the sample. Fatty acids are among the organic molecules that on Earth are chemical building blocks of life.
Living things produce fatty acids to help form cell membranes and perform various other functions. But fatty acids also can be made without life, through chemical reactions triggered by various geological processes, including the interaction of water with minerals in hydrothermal vents.
While there’s no way to confirm the source of the molecules identified, finding them at all is exciting for Curiosity’s science team for a couple of reasons.
Curiosity scientists had previously discovered small, simple organic molecules on Mars, but finding these larger compounds provides the first evidence that organic chemistry advanced toward the kind of complexity required for an origin of life on Mars.
This graphic shows the long-chain organic molecules decane, undecane, and dodecane. These are the largest organic molecules discovered on Mars to date. They were detected in a drilled rock sample called “Cumberland” that was analyzed by the Sample Analysis at Mars lab inside the belly of NASA’s Curiosity rover. The rover, whose selfie is on the right side of the image, has been exploring Gale Crater since 2012. An image of the Cumberland drill hole is faintly visible in the background of the molecule chains. NASA/Dan Gallagher The new study also increases the chances that large organic molecules that can be made only in the presence of life, known as “biosignatures,” could be preserved on Mars, allaying concerns that such compounds get destroyed after tens of millions of years of exposure to intense radiation and oxidation.
This finding bodes well for plans to bring samples from Mars to Earth to analyze them with the most sophisticated instruments available here, the scientists say.
“Our study proves that, even today, by analyzing Mars samples we could detect chemical signatures of past life, if it ever existed on Mars,” said Caroline Freissinet, the lead study author and research scientist at the French National Centre for Scientific Research in the Laboratory for Atmospheres and Space Observations in Guyancourt, France
In 2015, Freissinet co-led a team that, in a first, conclusively identified Martian organic molecules in the same sample that was used for the current study. Nicknamed “Cumberland,” the sample has been analyzed many times with SAM using different techniques.
NASA’s Curiosity rover drilled into this rock target, “Cumberland,” during the 279th Martian day, or sol, of the rover’s work on Mars (May 19, 2013) and collected a powdered sample of material from the rock’s interior. Curiosity used the Mars Hand Lens Imager camera on the rover’s arm to capture this view of the hole in Cumberland on the same sol as the hole was drilled. The diameter of the hole is about 0.6 inches. The depth of the hole is about 2.6 inches. NASA/JPL-Caltech/MSSS Curiosity drilled the Cumberland sample in May 2013 from an area in Mars’ Gale Crater called “Yellowknife Bay.” Scientists were so intrigued by Yellowknife Bay, which looked like an ancient lakebed, they sent the rover there before heading in the opposite direction to its primary destination of Mount Sharp, which rises from the floor of the crater.
The detour was worth it: Cumberland turns out to be jam-packed with tantalizing chemical clues to Gale Crater’s 3.7-billion-year past. Scientists have previously found the sample to be rich in clay minerals, which form in water. It has abundant sulfur, which can help preserve organic molecules. Cumberland also has lots of nitrates, which on Earth are essential to the health of plants and animals, and methane made with a type of carbon that on Earth is associated with biological processes.
Perhaps most important, scientists determined that Yellowknife Bay was indeed the site of an ancient lake, providing an environment that could concentrate organic molecules and preserve them in fine-grained sedimentary rock called mudstone.
“There is evidence that liquid water existed in Gale Crater for millions of years and probably much longer, which means there was enough time for life-forming chemistry to happen in these crater-lake environments on Mars,” said Daniel Glavin, senior scientist for sample return at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and a study co-author.
The recent organic compounds discovery was a side effect of an unrelated experiment to probe Cumberland for signs of amino acids, which are the building blocks of proteins. After heating the sample twice in SAM’s oven and then measuring the mass of the molecules released, the team saw no evidence of amino acids. But they noticed that the sample released small amounts of decane, undecane, and dodecane.
Because these compounds could have broken off from larger molecules during heating, scientists worked backward to figure out what structures they may have come from. They hypothesized these molecules were remnants of the fatty acids undecanoic acid, dodecanoic acid, and tridecanoic acid, respectively.
The scientists tested their prediction in the lab, mixing undecanoic acid into a Mars-like clay and conducting a SAM-like experiment. After being heated, the undecanoic acid released decane, as predicted. The researchers then referenced experiments already published by other scientists to show that the undecane could have broken off from dodecanoic acid and dodecane from tridecanoic acid.
The authors found an additional intriguing detail in their study related to the number of carbon atoms that make up the presumed fatty acids in the sample. The backbone of each fatty acid is a long, straight chain of 11 to 13 carbons, depending on the molecule. Notably, non-biological processes typically make shorter fatty acids, with less than 12 carbons.
It’s possible that the Cumberland sample has longer-chain fatty acids, the scientists say, but SAM is not optimized to detect longer chains.
Scientists say that, ultimately, there’s a limit to how much they can infer from molecule-hunting instruments that can be sent to Mars. “We are ready to take the next big step and bring Mars samples home to our labs to settle the debate about life on Mars,” said Glavin.
This research was funded by NASA’s Mars Exploration Program. Curiosity’s Mars Science Laboratory mission is led by NASA’s Jet Propulsion Laboratory in Southern California; JPL is managed by Caltech for NASA. SAM (Sample Analysis at Mars) was built and tested at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. CNES (the French Space Agency) funded and provided the gas chromatograph subsystem on SAM. Charles Malespin is SAM’s principal investigator.
By Lonnie Shekhtman
NASA’s Goddard Space Flight Center, Greenbelt, Md.
View the full article
-
By NASA
X-ray: NASA/CXC/SAO/Univ Mexico/S. Estrada-Dorado et al.; Ultraviolet: NASA/JPL; Optical: NASA/ESA/STScI (M. Meixner)/NRAO (T.A. Rector); Infrared: ESO/VISTA/J. Emerson; Image Processing: NASA/CXC/SAO/K. Arcand; A planet may have been destroyed by a white dwarf at the center of a planetary nebula — the first time this has been seen. As described in our latest press release, this would explain a mysterious X-ray signal that astronomers have detected from the Helix Nebula for over 40 years. The Helix is a planetary nebula, a late-stage star like our Sun that has shed its outer layers leaving a small dim star at its center called a white dwarf.
This composite image contains X-rays from Chandra (magenta), optical light data from Hubble (orange, light blue), infrared data from ESO (gold, dark blue), and ultraviolet data from GALEX (purple) of the Helix Nebula. Data from Chandra indicates that this white dwarf has destroyed a very closely orbiting planet.
This artist’s impression shows a planet (left) that has approached too close to a white dwarf (right) and been torn apart by tidal forces from the star. The white dwarf is in the center of a planetary nebula depicted by the blue gas in the background. The planet is part of a planetary system, which includes one planet in the upper left and another in the lower right. The besieged planet could have initially been a considerable distance from the white dwarf but then migrated inwards by interacting with the gravity of other planets in the system.CXC/SAO/M.Weiss An artist’s concept shows a planet (left) that has approached too close to a white dwarf (right) and is being torn apart by tidal forces from the star. The white dwarf is in the center of a planetary nebula depicted by the blue gas in the background. The planet is part of a planetary system, which includes one planet in the upper left and another in the lower right. The besieged planet could have initially been a considerable distance from the white dwarf but then migrated inwards by interacting with the gravity of the other planets in the system.
Eventually debris from the planet will form a disk around the white dwarf and fall onto the star’s surface, creating the mysterious signal in X-rays that astronomers have detected for decades.
Dating back to 1980, X-ray missions, such as the Einstein Observatory and ROSAT telescope, have picked up an unusual reading from the center of the Helix Nebula. They detected highly energetic X-rays coming from the white dwarf at the center of the Helix Nebula named WD 2226-210, located only 650 light-years from Earth. White dwarfs like WD 2226-210 do not typically give off strong X-rays.
In about 5 billion years, our Sun will run out of fuel and expand, possibly engulfing Earth. These end stages of a star’s life can be utterly beautiful as is the case with this planetary nebula called the Helix Nebula.X-ray: NASA/CXC/SAO/Univ Mexico/S. Estrada-Dorado et al.; Ultraviolet: NASA/JPL; Optical: NASA/ESA/STScI (M. Meixner)/NRAO (T.A. Rector); Infrared: ESO/VISTA/J. Emerson; Image Processing: NASA/CXC/SAO/K. Arcand; A new study featuring the data from Chandra and XMM-Newton may finally have settled the question of what is causing these X-rays from WD 2226-210: this X-ray signal could be the debris from a destroyed planet being pulled onto the white dwarf. If confirmed, this would be the first case of a planet seen to be destroyed by the central star in a planetary nebula.
Observations by ROSAT, Chandra, and XMM-Newton between 1992 and 2002 show that the X-ray signal from the white dwarf has remained approximately constant in brightness during that time. The data, however, suggest there may be a subtle, regular change in the X-ray signal every 2.9 hours, providing evidence for the remains of a planet exceptionally close to the white dwarf.
Previously scientists determined that a Neptune-sized planet is in a very close orbit around the white dwarf — completing one revolution in less than three days. The researchers in this latest study conclude that there could have been a planet like Jupiter even closer to the star. The besieged planet could have initially been a considerable distance from the white dwarf but then migrated inwards by interacting with the gravity of other planets in the system. Once it approached close enough to the white dwarf the gravity of the star would have partially or completely torn the planet apart.
WD 2226-210 has some similarities in X-ray behavior to two other white dwarfs that are not inside planetary nebulas. One is possibly pulling material away from a planet companion, but in a more sedate fashion without the planet being quickly destroyed. The other white dwarf is likely dragging material from the vestiges of a planet onto its surface. These three white dwarfs may constitute a new class of variable, or changing, object.
A paper describing these results appears in The Monthly Notices of the Royal Astronomical Society and is available online. The authors of the paper are Sandino Estrada-Dorado (National Autonomous University of Mexico), Martin Guerrero (The Institute of Astrophysics of Andalusia in Spain), Jesús Toala (National Autonomous University of Mexico), Ricardo Maldonado (National Autonomous University of Mexico), Veronica Lora (National Autonomous University of Mexico), Diego Alejandro Vasquez-Torres (National Autonomous University of Mexico), and You-Hua Chu (Academia Sinica in Taiwan).
NASA’s Marshall Space Flight Center manages the Chandra program. The Smithsonian Astrophysical Observatory’s Chandra X-ray Center controls science operations from Cambridge, Massachusetts, and flight operations from Burlington, Massachusetts.
Read more from NASA’s Chandra X-ray Observatory.
Learn more about the Chandra X-ray Observatory and its mission here:
https://www.nasa.gov/chandra
https://chandra.si.edu
Visual Description
This release features two images; a composite image of the Helix Nebula, and an artist’s rendering of a planet’s destruction, which may be occurring in the nebula’s core.
The Helix Nebula is a cloud of gas ejected by a dying star, known as a white dwarf. In the composite image, the cloud of gas strongly resembles a creature’s eye. Here, a hazy blue cloud is surrounded by misty, concentric rings of pale yellow, rose pink, and blood orange. Each ring appears dusted with flecks of gold, particularly the outer edges of the eye-shape.
The entire image is speckled with glowing dots in blues, whites, yellows, and purples. At the center of the hazy blue gas cloud, a box has been drawn around some of these dots including a bright white dot with a pink outer ring, and a smaller white dot. The scene which may be unfolding inside this box has been magnified in the artist’s rendering.
The artist’s digital rendering shows a possible cause of the large white dot with the pink outer ring. A brilliant white circle near our upper right shows a white dwarf, the ember of a dying star. At our lower left, in the relative foreground of the rendering, is what remains of a planet. Here, the planet resembles a giant boulder shedding thousands of smaller rocks. These rocks flow off the planet’s surface, pulled back toward the white dwarf in a long, swooping tail. Glowing orange fault lines mar the surface of the crumbling planet. In our upper left and lower right, inside the hazy blue clouds which blanket the rendering, are two other, more distant planets. After the rocks from the planet start striking the surface of the white dwarf, X-rays should be produced.
News Media Contact
Megan Watzke
Chandra X-ray Center
Cambridge, Mass.
617-496-7998
mwatzke@cfa.harvard.edu
Lane Figueroa
Marshall Space Flight Center, Huntsville, Alabama
256-544-0034
lane.e.figueroa@nasa.gov
Explore More
6 min read NASA’s Hubble Finds Kuiper Belt Duo May Be Trio
The puzzle of predicting how three gravitationally bound bodies move in space has challenged mathematicians…
Article 12 mins ago 6 min read NASA’s Webb Exposes Complex Atmosphere of Starless Super-Jupiter
An international team of researchers has discovered that previously observed variations in brightness of a…
Article 1 day ago 1 min read Hubble Captures New View of Colorful Veil
In this NASA/ESA Hubble Space Telescope image, Hubble once again lifts the veil on a…
Article 4 days ago Keep Exploring Discover More Topics From NASA
Missions
Humans in Space
Climate Change
Solar System
View the full article
-
-
Check out these Videos
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.