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NASA’s Webb Discovers Hidden Planet in Famous Star System

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Jul 15, 2026 - 14:25

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NASA’s Webb Discovers Hidden Planet in Famous Star System

Artist's concept of the Beta Pictoris planetary system. One edge of a smooth, dusty disk that looks like cloud wisps extends across the upper third of the image at an angle from 9 o’clock to 2 o’clock. Just below that, in the left third of the image, the star glows white and is small. Just to the left of the star there is a tiny white dot, planet Beta Pictoris c. To the right of the star, about twice the distance between Beta Pictoris c and the star is another bright dot, representing planet Beta Pictoris b. A third planet, Beta Pictoris d is larger than the other two, and appears in the right third of the illustration. The planet has subtle orange cloud bands, and the side facing the star is illuminated. Below this planet, the other wispy edge of the dusty disk that circles the star crosses the bottom right corner of the illustration below Beta Pictoris d from 4 o’clock to 7 o’clock. The black background of space is speckled with distant stars. The words

This artist’s concept shows the Beta Pictoris system with the discovered giant exoplanet Beta Pictoris d at the right. It has the widest orbit of the known three exoplanets within the system.

Credits:
Illustration: NASA, ESA, CSA, STScI, Ralf Crawford (STScI)

Astronomers using NASA’s James Webb Space Telescope have discovered a giant planet outside our solar system, called an exoplanet, hiding within one of the most intensely studied planetary systems in our Milky Way galaxy.

The young, nearby star Beta Pictoris was already known to host two giant planets: Beta Pictoris b, one of the first exoplanets ever directly imaged, and Beta Pictoris c. The newly identified Beta Pictoris d makes it only the second planetary system known to contain at least three imaged planets. Unlike Beta Pictoris b and c, however, Beta Pictoris d was discovered not by identifying a bright point of light, but by detecting the unique chemical fingerprint of its atmosphere, a technique that could transform the search for worlds around other stars.

“This discovery adds another piece to an already fascinating planetary system,” said Aidan Gibbs, lead author of a new study published Wednesday in the Astrophysical Journal Letters and a postdoctoral researcher at the University of California, San Diego. “Beta Pictoris has long served as a laboratory for understanding how planetary systems form and evolve, and now we have another planet helping us tell that story.”

Image: Beta Pictoris System (Artist’s Concept)

This artist’s concept shows the Beta Pictoris system with the discovered giant exoplanet Beta Pictoris d at the right. It has the widest orbit of the known three exoplanets within the system.

Illustration: NASA, ESA, CSA, STScI, Ralf Crawford (STScI)

Familiar system, new surprise

Located 63 light-years from Earth and about 23 million years old, Beta Pictoris is a nearby system in the Milky Way offering a rare glimpse of the interactions between newborn planets and the disk of dust and debris left behind from their formation.

The team estimates that the newfound Beta Pictoris d is likely at least two times the mass of Jupiter, making it the smallest of the three known giant planets in the system. Modeling suggests it likely circles around its star at about 30 astronomical units, comparable to the region occupied by Neptune in our own solar system. It’s the widest orbit of the known three planets, but still located inside the inner edge of the debris disk.

Although astronomers were not searching for another planet with Webb, Beta Pictoris d emerged while the team was using the telescope’s NIRSpec (Near-Infrared Spectrograph) to study the atmosphere of Beta Pictoris b. Specifically, they used NIRSpec’s Integral Field Unit, which obtains both an image and a spectrum from each pixel in an image.

“We weren’t looking for a new planet,” said Gibbs. “We were trying to understand one we already knew existed. Then, this telltale signal appeared in the data where we didn’t expect it.”

This signal was a series of peaks and troughs within the spectroscopic data where the team expected to see a smooth spectrum from light bouncing off dust. It was a distinctive pattern of carbon monoxide absorption lines, spread out like a barcode, an expected feature in giant planet atmospheres.

Because spectroscopy not only reveals chemical composition, but the motion of an object, the team was able to also extract radial velocity from the data. The team determined the planet’s speed, position, and alignment with the debris disk were all consistent with something orbiting Beta Pictoris rather than a background star or brown dwarf with carbon monoxide in its atmosphere.

“There was an unexpected bright source of light within the Integral Field Unit imaging, but we’ve learned not to trust bright blobs in images,” said Jean-Baptiste Ruffio, a research scientist at University of California, San Diego and principal investigator of the first Webb observations where the discovery was made. “They can be instrumental artifacts or other structures in the debris disk. By obtaining a spectrum at the same time as the image, we were able to quickly confirm our suspicions.”

Follow-up observations with Webb’s MIRI (Mid-Infrared Instrument) through a Director’s Discretionary Time request detected water vapor and methane, further confirming the planet’s identity while providing a richer look at the atmosphere of the planet.

Unlike traditional imaging, the spectroscopic approach allowed researchers to identify the planet and begin studying its atmosphere from the very first observation.

“A spectrum contains an incredible amount of information,” Ruffio said. “You don’t just learn that something is a planet; you immediately begin learning about its temperature, chemistry, and motion.”

A separate imaging study led by Ben Sutlieff of the University of Edinburgh and Markus Bonse of the European Southern Observatory complements the team’s findings with data from the European Southern Observatory’s Very Large Telescope and Webb’s NIRCam (Near-Infrared Camera) and independently confirmed the existence of Beta Pictoris d.

Image: Beta Pictoris System (NIRSpec IFU Image and Spectrum)

Infographic titled “Gas Giant Exoplanet Beta Pictoris d; Atmospheric Composition.” The image at the left shows two exoplanets of the Beta Pictoris system. At the center, there is a white star symbol, which represents light blocked from the host star. Immediately to the left of the star symbol, there is a bright orange-whitesh smudge, labeled b. To the right of the star symbol is a blurry orange smudge labeled d. There is a white circle around this smudge with lines drawn to the spectrum at the right. The x-axis is labeled “Wavelength of Light” and extends from 4.2 to 5.2 microns. The y-axis is labeled “Brightness.” An up arrow is labeled “brighter,” a down arrow “dimmer.” There are two jagged horizontal lines across the graph. One is white, then other is maroon (the former labeled “Webb data”, the latter labeled “Best fit model” in the bottom left corner). A blue vertical column spanning from about 4.3 microns to 5 microns is labeled Carbon Monoxide, CO.

Researchers used the NIRSpec (Near-Infrared Spectrograph) Integral Field Unit on NASA’s James Webb Space Telescope to map chemical contents of the Beta Pictoris system. As a result, they discovered a third planet, Beta Pictoris d, orbiting the young star.

Image: NASA, ESA, CSA, STScI, Leah Hustak (STScI); Science: Aidan Gibbs (UC San Diego), Jean-Baptiste Ruffio (UC San Diego), Alexis Bidot (STScI); Image Processing: Alyssa Pagan (STScI)

Image: Beta Pictoris System (NIRSpec IFU Image Annotated)

An image of the Beta Pictoris system, with two exoplanets shown. The view is black. At the center of the image, there is a white star symbol, which represents light blocked from the host star. Immediately to the left of the star symbol, there is a bright orange-whitesh smudge, labeled b. To the right of the star symbol, further away, is a blurry orange smudge labeled d. There is a blue dashed circle around the entire system, labeled “size of Neptune’s orbit.”

The newly discovered third planet orbiting Beta Pictoris, Beta Pictoris d, is seen in reconstructed imagery from NASA’s James Webb Space Telescope’s NIRSpec (Near-Infrared Spectrograph).

Image: NASA, ESA, CSA, STScI; Science: Aidan Gibbs (UC San Diego), Jean-Baptiste Ruffio (UC San Diego); Image Processing: Alyssa Pagan (STScI)

Seeing through cosmic fog

Beta Pictoris d remained hidden for years because it lies within one of the brightest debris disks known.

The dusty disk acts like fog, scattering light from the star, making it difficult for conventional imaging techniques to distinguish planets from surrounding structures. The team’s spectroscopic method with Webb effectively ignored that dust, isolating only the narrow molecular signatures unique to a planetary atmosphere.

Scientists say the planet’s presence may help explain why the famous debris disk has such a sharply defined inner edge and other puzzling structures. In fact, astronomers had already predicted the existence of a planet like Beta Pictoris d to account for the disk’s unusual structure.

Beyond expanding our understanding of Beta Pictoris, the discovery demonstrates a powerful new way to find exoplanets.

This is the first directly imaged planet discovered primarily through moderate-resolution spectroscopy, showing that astronomers can identify worlds in complex environments through their atmospheric fingerprints rather than relying solely on traditional coronagraphic imaging.

The researchers plan to continue analyzing Webb’s observations to better determine the planet’s temperature, atmospheric composition, and orbit, providing an even more detailed view of one of astronomy’s most iconic planetary systems.

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

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Related Images & Videos

Beta Pictoris System (Artist’s Concept)

This artist’s concept shows the Beta Pictoris system with the discovered giant exoplanet Beta Pictoris d at the right. It has the widest orbit of the known three exoplanets within the system.

Infographic titled u201cGas Giant Exoplanet Beta Pictoris d; Atmospheric Composition.u201d The image at the left shows two exoplanets of the Beta Pictoris system. At the center, there is a white star symbol, which represents light blocked from the host star. Immediately to the left of the star symbol, there is a bright orange-whitesh smudge, labeled b. To the right of the star symbol is a blurry orange smudge labeled d. There is a white circle around this smudge with lines drawn to the spectrum at the right. The x-axis is labeled u201cWavelength of Lightu201d and extends from 4.2 to 5.2 microns. The y-axis is labeled u201cBrightness.u201d An up arrow is labeled u201cbrighter,u201d a down arrow u201cdimmer.u201d There are two jagged horizontal lines across the graph. One is white, then other is maroon (the former labeled u201cWebb datau201d, the latter labeled u201cBest fit modelu201d in the bottom left corner). A blue vertical column spanning from about 4.3 microns to 5 microns is labeled Carbon Monoxide, CO.

Beta Pictoris System (NIRSpec IFU Image and Spectrum)

Beta Pictoris System (NIRSpec IFU Image Annotated)

The newly discovered third planet orbiting Beta Pictoris, Beta Pictoris d, is seen in reconstructed imagery from NASA’s James Webb Space Telescope’s NIRSpec (Near-Infrared Spectrograph).