<\/p>\n
Beta Pictoris, a young planetary system located just 63 light-years away, continues to intrigue scientists even after decades of in-depth study. It possesses the first dust disk imaged around another star \u2014 a disk of debris produced by collisions between asteroids, comets, and planetesimals. Observations from NASA\u2019s Hubble Space Telescope revealed a second debris disk in this system, inclined with respect to the outer disk, which was seen first. Now, a team of astronomers using NASA\u2019s James Webb Space Telescope to image the Beta Pictoris system (Beta Pic) has discovered a new, previously unseen structure.<\/p>\n
The team, led by Isabel Rebollido of the Astrobiology Center in Spain, used Webb\u2019s NIRCam (Near-Infrared Camera)<\/a> and MIRI (Mid-Infrared Instrument)<\/a> to investigate the composition of Beta Pic\u2019s previously detected main and secondary debris disks. The results exceeded their expectations, revealing a sharply inclined branch of dust, shaped like a cat\u2019s tail, that extends from the southwest portion of the secondary debris disk.<\/p>\n \u201cBeta Pictoris is the debris disk that has it all: It has a really bright, close star that we can study very well, and a complex cirumstellar environment with a multi-component disk, exocomets, and two imaged exoplanets,\u201d said Rebollido, lead author of the study. \u201cWhile there have been previous observations from the ground in this wavelength range, they did not have the sensitivity and the spatial resolution that we now have with Webb, so they didn\u2019t detect this feature.\u201d<\/p>\n A Star\u2019s Portrait Improved with Webb<\/strong><\/p>\n Even with Webb or JWST, peering at Beta Pic in the right wavelength range \u2014 in this case, the mid-infrared \u2014 was crucial to detect the cat\u2019s tail, as it only appeared in the MIRI data. Webb\u2019s mid-infrared data also revealed differences in temperature between Beta Pic\u2019s two disks, which likely is due to differences in composition.<\/p>\n \u201cWe didn\u2019t expect Webb to reveal that there are two different types of material around Beta Pic, but MIRI clearly showed us that the material of the secondary disk and cat\u2019s tail is hotter than the main disk,\u201d said Christopher Stark, a co-author of the study at NASA\u2019s Goddard Space Flight Center in Greenbelt, Maryland. \u201cThe dust that forms that disk and tail must be very dark, so we don\u2019t easily see it at visible wavelengths \u2014 but in the mid-infrared, it\u2019s glowing.\u201d<\/p>\n To explain the hotter temperature, the team deduced that the dust may be highly porous \u201corganic refractory material,\u201d similar to the matter found on the surfaces of comets and asteroids in our solar system. For example, a preliminary analysis of material sampled from asteroid Bennu by NASA\u2019s OSIRIS-REx mission<\/a> found it to be very dark and carbon-rich, much like what MIRI detected at Beta Pic.<\/p>\n The Tail\u2019s Puzzling Beginning Warrants Future Research<\/strong><\/p>\n However, a major lingering question remains: What could explain the shape of the cat\u2019s tail, a uniquely curved feature unlike what is seen in disks around other stars?<\/p>\n Rebollido and the team modeled various scenarios in an attempt to emulate the cat\u2019s tail and unravel its origins. Though further research and testing is required, the team presents a strong hypothesis that the cat\u2019s tail is the result of a dust production event that occurred a mere one hundred years ago.<\/p>\n \u201cSomething happens \u2014 like a collision \u2014 and a lot of dust is produced,\u201d shared Marshall Perrin, a co-author of the study at the Space Telescope Science Institute in Baltimore, Maryland. \u201cAt first, the dust goes in the same orbital direction as its source, but then it also starts to spread out. The light from the star pushes the smallest, fluffiest dust particles away from the star faster, while the bigger grains do not move as much, creating a long tendril of dust.\u201d<\/p>\n \u201cThe cat\u2019s tail feature is highly unusual, and reproducing the curvature with a dynamical model was difficult,\u201d explained Stark. \u201cOur model requires dust that can be pushed out of the system extremely rapidly, which again suggests it\u2019s made of organic refractory material.\u201d<\/p>\n![](\"https:\/\/www.nasa.gov\/wp-content\/uploads\/2024\/01\/webb-stsci-01hkancq4d5k4gyw89awd3ety0.png\")