There are new observations in the light.
The planetary system around the star is still fascinating after decades of study. The new chapter of the story has been unlocked by NASA and includes new information about the composition of the debris disks and a dust trail resembling a cat's tail. A team of astronomer theorize that this feature is a new addition to the planetary system.
Scientists have been studying the young planetary system for decades, but it continues to intrigue them. It has the first dust disk imaged around another star, a disk of debris produced by asteroids, comets, and planetesimals. The Hubble Space Telescope observed a second debris disk in this system, which was seen first. Astronomers using NASA's James Webb Space Telescope have discovered a new structure in the system. The team, led by Isabel Rebollido of the Astrobiological Center in Spain, used a Near-Infrared Camera and a Mid-Infrared Camera to investigate the composition of the main and secondary debris disks. The results showed a branch of dust that was shaped like a cat's tail and extended from the southwest portion of the debris disk. Reboll said that the debris disk contains a bright, close star, exocomets, and two imaged exoplanets. They didn't detect this feature because they didn't have the sensitivity and the spatial resolution that we now have with Webb.
The animation depicts the creation of the cat's tail, which is estimated to span 10 billion miles. The tail of the cat might be the result of a dust production event that took place a hundred years ago. The star's light pushes the smallest, fluffiest dust particles away from the star faster, while bigger grains do not move as much, creating a trail of dust. The observed angle is created by our perspective along with the tail's curve, while the tendril of dust only leaves the disk at a five degree incline. The image of a star has been improved with the help of the astronomer.
The cat's tail was only visible in the MIRI data, so it was crucial to look for it in the right wavelength range. Differences in temperature between the two disks are likely due to differences in composition. Christopher Stark, a co-author of the study at NASA, said that the material of the secondary disk and cat's tail is hotter than the main disk. It is difficult to see the disk and tail at visible wavelength, but in the mid-IR it is glowing.
The team deduced that the dust may be porous and similar to the material found on the surface of comets and asteroids. A preliminary analysis of material from asteroid Bennu by NASA's OSIRIS-REx mission found it to be very dark and carbon-rich.
The shape of the cat's tail, a uniquely curved feature unlike what is seen in disks around other stars, is a nagging question. Rebollido and the team modeled scenarios to try and understand the origins of the cat's tail. The team presented a strong hypothesis that the cat's tail is the result of a dust production event that occurred one hundred years ago. Marshall Perrin, a co-author of the study, shared that a lot of dust is produced when something happens. The dust goes in the same direction as its source, but it also starts to spread. 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.
The cat has a unique tail feature that was difficult to reproduce with a model.
The team's preferred model explains the angle of the tail away from the disk as an optical illusion. The angle of the tail is created by our perspective and the arcs of material only leave the disk at a five degree incline. The team estimates that the amount of dust within the cat's tail is equivalent to 10 billion miles of asteroids. The asymmetric extension of the inclined inner disk could be explained by a dust production event within the debris disks. A clump of carbon monoxide is located near the cat's tail, and it could be the result of recent collisional dust production. The star's radiation should break down CO within one hundred years, so this still-present concentration of gas is evidence of the same event. We have a new glimpse into these planetary systems, even when looking at the most well-studied objects.
The results were presented in a press conference at the 243rd meeting of the American Astronomical Society. NASA is leading a program called "Wbb" that is investigating mysteries in our solar system and looking beyond to distant worlds.