These two photographs are of the dusty particles disk round AU Mic, a pink dwarf star positioned 32 light-years away within the southern constellation Microscopium. The group used Webb’s Near-Infrared Camera (NIRCam) to review AU Mic. NIRCam’s coronagraph, which blocked the extraordinary mild of the central star, allowed the group to review the area very near the star. The location of the star, which is masked out, is marked by a white, graphical illustration on the middle of every picture. The area blocked by the coronagraph is proven by a dashed circle.
Webb supplied photographs at 3.56 microns (prime, blue) and 4.44 microns (backside, pink). The group discovered that the disk was brighter on the shorter or “bluer” wavelength, seemingly which means that it incorporates lots of fantastic mud that’s extra environment friendly at scattering shorter wavelengths of sunshine.
The NIRCam photographs allowed the researchers to hint the disk, which spans a diameter of 60 astronomical items (5.6 billion miles), as near the star as 5 astronomical items (460 million miles) – the equal of Jupiter’s orbit in our photo voltaic system. The photographs have been extra detailed and brighter than the group anticipated, and scientists have been capable of picture the disk nearer to the star than anticipated.
Credit: Science: NASA, ESA, CSA, Kellen Lawson (NASA-GSFC), Joshua E. Schlieder (NASA-GSFC), Image Processing: Alyssa Pagan (STScI)
Results will assist in future searches for big planets in broad orbits
Not so very far-off in cosmic phrases, the dusty leftovers of planet formation encompass the pink dwarf star AU Mic. Caused by smash-ups of small, strong objects referred to as planetesimals, these remnants encircle the small star in an infinite particles disk. Now, Webb is offering scientists with detailed, never-before-seen views of AU Mic’s dusty disk in infrared mild, together with the area very near the star. These photographs provide clues to the make-up of the particles disk and the historical past of the star system.
Although imaging the disk is important, the group’s final purpose is to seek for big planets in broad orbits, much like the gasoline and ice giants of our photo voltaic system. By delving into new, uncharted territory in direct imaging round low-mass stars, this work brings them one, large step nearer to reaching that purpose.
These coronagraphic photographs of a disk across the star AU Microscopii, captured by Webb’s Near-Infrared Camera (NIRCam), present compass arrows, scale bar, and coloration key for reference.
The north and east compass arrows present the orientation of the picture on the sky. Note that the connection between north and east on the sky (as seen from under) is flipped relative to course arrows on a map of the bottom (as seen from above).
The scale bar is labeled in astronomical items, or A.U., which is the common distance between the Earth and the Sun. The area of view proven on this picture is roughly 100 A.U. throughout.
This picture reveals invisible near-infrared and mid-infrared wavelengths of sunshine which were translated into visible-light colours. The coloration key reveals which NIRCam filters have been used when accumulating the sunshine. The coloration of every filter title is the seen mild coloration used to signify the infrared mild that passes by way of that filter.
Credit: Science: NASA, ESA, CSA, Kellen Lawson (NASA-GSFC), Joshua E. Schlieder (NASA-GSFC), Image Processing: Alyssa Pagan (STScI)
NASA’s James Webb Space Telescope has imaged the inner workings of a dusty disk surrounding a nearby red dwarf star. These observations represent the first time the previously known disk has been imaged at these infrared wavelengths of light. They also provide clues to the composition of the disk.
The star system in question, AU Microscopii or AU Mic, is located 32 light-years away in the southern constellation Microscopium. It’s approximately 23 million years old, meaning that planet formation has ended since that process typically takes less than 10 million years. The star has two known planets, discovered by other telescopes. The dusty debris disk that remains is the result of collisions between leftover planetesimals – a more massive equivalent of the dust in our solar system that creates a phenomenon known as zodiacal light.
“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 Jupiter’s orbit in our solar system.
“Our first look at the data far exceeded expectations. It was more detailed than we expected. It was brighter than we expected. We detected the disk closer in than we expected. We’re hoping that as we dig deeper, there’s going to be some more surprises that we hadn’t predicted,” stated Schlieder.
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, Saturn, or the ice giants of our solar system. Such worlds are very difficult to detect around distant stars using either the transit or radial velocity methods.
“This is the first time that we really have sensitivity to directly observe planets with wide orbits that are significantly lower in mass than Jupiter and Saturn. This really is new, uncharted territory in terms of direct imaging around low-mass stars,” explained Lawson.
These results are being presented today in a press conference at the 241st meeting of the American Astronomical Society. The observations were obtained as part of Webb’s Guaranteed Time program 1184.
The James Webb Space Telescope is the world’s premier space science observatory. Webb will solve mysteries in our solar system, look beyond to distant worlds around other stars, and probe 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).
