The Webb Space Telescope is revealing dusty remnants of planet formation never seen before

AU Mic (Webb NIRCam)

These two images of the dusty debris disk around AU Mic, a red dwarf star located 32 light-years away in the southern constellation Microscopium. The team used a near infrared webcam (NIRCam) to study the AU microphone. NIRCam’s crown, which blocked out the intense light of the central star, allowed the team to study the region very close to the star. The location of the star, which is hidden, is marked with a white graphic representation in the center of each image. The area restricted by coronagraph is shown by a dashed circle.
Webb provided images at 3.56 μm (top, blue) and 4.44 μm (bottom, red). The team found that the disk was brightest at the shortest or “bluest” wavelength, which likely means it contains a lot of fine dust that is more efficient at scattering shorter wavelengths of light.
The NIRCam images allowed the researchers to track the disk, which spans a diameter of 60 astronomical units (5.6 billion miles), as close to the star as 5 astronomical units (460 million miles)—equivalent to the orbit of Jupiter in our solar system. The images were more detailed and brighter than the team had expected, and the scientists were able to image the disk much closer to the star than expected.
Credit: Science: NASA, ESA, CSA, Kellen Lawson (NASA-GSFC), Joshua E. Schlieder (NASA-GSFC), Image Processing: Alyssa Pagan (STScI)

The findings will aid future searches for giant planets in wide orbits

Not too far out in cosmological terms, the red dwarf star AU Mic is surrounded by the dusty remnants of planet formation. Shattered by small, solid objects called planetesimals, these remnants surround the young star in an enormous disk of debris. Now, Webb is providing scientists with never-before-seen detailed views of AU Mic’s dusty disk in infrared light, including the region very close to the star. These images provide clues to the formation of the debris disk and the history of the star system.

Although imaging the disk is important, the team’s ultimate goal is to search for giant planets in wide orbits, similar to the gas and ice giants in our solar system. By delving into new, uncharted territory in direct imaging of low-mass stars, this work brings them one big step closer to achieving that goal.

AU Microphone Compass (Webb NIRCam)

These coronal images of the disk around the star AU Microscopii, taken with the Webb’s Near Infrared Camera (NIRCam), show compass arrows, a scale bar, and a color key for reference.
The north and east compass arrow shows the image’s direction in the sky. Note that the relationship between north and east in the sky (as seen from below) is inverted relative to the directional arrows on the Earth map (as seen from above).
The scale bar is known in Astronomical Units, or AU, and is the average distance between Earth and the Sun. The field of view shown in this image is about 100 astronomical units.
This image shows the wavelengths of near, mid, and invisible infrared, which are translated into the colors of visible light. The color key indicates which NIRCam filters were used when collecting the light. The color of each filter name is the color of the visible light used to represent the infrared light passing through that filter.
Credit: Science: NASA, ESA, CSA, Kellen Lawson (NASA-GSFC), Joshua E. Schlieder (NASA-GSFC), Image Processing: Alyssa Pagan (STScI)

“A debris disk is continuously replenished by collisions of planetesimals. By studying it, we get a unique window into the recent dynamical history of this system,” said Kellen Lawson of NASA’s Goddard Space Flight Center, lead author on the study and a member of the research team that studied AU Mic.

“This system is one of the very few examples of a young star, with known exoplanets, and a debris disk that is near enough and bright enough to study holistically using Webb’s uniquely powerful instruments,” said Josh Schlieder of NASA’s Goddard Space Flight Center, principal investigator for the observing program and a study co-author.

The team used Webb’s Near-Infrared Camera (NIRCam) to study AU Mic. With the help of NIRCam’s coronagraph, which blocks the intense light of the central star, they were able to study the region very close to the star. The NIRCam images allowed the researchers to trace the disk as close to the star as 5 astronomical units (460 million miles) – the equivalent of

The observing program obtained images at wavelengths of 3.56 and 4.44 microns. The team found that the disk was brighter at the shorter wavelength, or “bluer,” likely meaning that it contains a lot of fine dust that is more efficient at scattering shorter wavelengths of light. This finding is consistent with the results of prior studies, which found that the radiation pressure from AU Mic — unlike that of more massive stars — would not be strong enough to eject fine dust from the disk.

While detecting the disk is significant, the team’s ultimate goal is to search for giant planets in wide orbits, similar to Jupiter,

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