This month, astronomers released the largest collection of sharp, detailed images of the disk of debris around young stars, depicting the great variety of shapes and sizes of stellar systems during the years of their creation of the Prime Planet. Surprisingly, almost everyone showed evidence of the planets.
The images were taken over a four-year period by an accurate instrument, the Gemini Planet Imager (GPI), mounted on an 8-meter Gemini South telescope in Chile. The GPI uses a modern artificially adapted optical system to remove atmospheric dimming, providing the sharpest images with multiple dates on these drives.
Ground-based instruments, such as the GPI, which has been updated to make similar observations in the northern sky from the Hawaiian Gemini Northern Telescope, may screen stars from suspicious debris discs to determine which targets are more powerful, but expensive, telescopes. Several 20-, 30-, and 40-meter telescopes, such as the giant Magellan Telescope and the extremely large telescope, will be available online in the next decade, while the orbital James Webb Space Telescope is expected to be launched in 2021.
"It's easier to detect a disk full of dust than the planets, so you find dust, and then you know you're pointing to your James Webb Space Telescope or your Nancy Gray's Roman Space Telescope in those systems, reducing the number of stars." You have to expand to find these planets in the first place, ”said Tom Espostom, a graduate student at the University of California, Berkeley.
Esposito is the author of the first paper describing the results that appeared on June 15th Astronomical Journal.
Comet belts around other stars
In the images, the debris disk is the equivalent of the Kuieri belt in our solar system, the solar system, which is about 40 times farther from Earth than the Earth – Earth – beyond the orbit of Neptune – and full of rocks, dust and ice that never became part of any planet in our solar system. . Belts, ice and rock balls – from time to time – swim in the inner system of the sun, sometimes destroying the earth, but also provide life-giving materials such as water, carbon and oxygen.
Of the 26 images from the debris disc found by the Gemini Planet Imager (GPI), 25 had “holes” with a central star that were likely created from planets that cleared rocks and dust. Seven of the 26 people were unknown; The early images of the other 19 were not as sharp as those from the GPI and often did not have the resolution to explore the inner hole. The survey doubled the number of debris discs depicted with such a high resolution.
"One of the things we've found is that this so-called The discs are really rings that are clean inside. ” – said Esposito, who is also a researcher at the SETI Institute in Mountain View, California. "The GPI clearly had a vision of the inner regions near the star, while in the past, by observing the Hubble Space Telescope and old instruments from the ground, I could not see close to the star to see the hole around it."
The GPI contains a corona that blocks the star's light, allowing it to be seen as close as one astronomical unit (AU) of the star, or the Earth's distance from our sun: 93 million miles.
The GPI targets 104 stars that shone extraordinarily brightly in infrared light, indicating that they were surrounded by debris that reflected starlight or warmed the star. The instrument launched a polarized near-infrared light with small particles of scattered dust, about a millimeter (1 micron) about a tenth, which is probably the result of a collision between the larger rocks in the debris disk.
"Until now, there has been no systematic examination of young debris, almost the same size, with the same instrument, using the same observational regimes and methods," Esposito said. "We've recorded these 26 pieces of debris with very consistent disk quality, where we can really compare the observations, which is unique in terms of polling disk debris."
The seven debris discs, never depicted in this picture, were 13 discs among the moving stars, but the deer leap, members of a group called the Scorpius-Centaurus stellar association, is located between 100 and 140 on Earth Friday, or about 400 Light. Years.
“It’s like a wonderful fishing spot; Our success rate is much higher than anything we've ever done, "said Paul Callas, a professor of astronomy who studied UC Berkeley and is the author of the second paper. Because all seven stars were born in about the same region, at about the same time, "this group is in itself a mini-laboratory where we can compare and differentiate many planetary gardens that are evolving simultaneously under a number of conditions. We didn't have it, "Esposito added.
Of the 104 stars observed, 75 did not have the size or density of the disk found by the GPI, although they may have been surrounded by debris left over from the formation of the planet. Three other stars have been recorded as hosting discs belonging to the earlier "protoplanetary" phase of evolution.
What did our solar system look like as a child?
The size of the debris discs varies, but most range from 20 to 100 AU. It was around stars that were estimated to be several hundred million years old by tens of millions of years, this is a very dynamic period for the evolution of the planets. Most of them were bigger and brighter than the sun.
One star, HD 156623, which had no hole in the center of the debris disk, was one of the youngest in the group to fit the theories of how planets formed. Initially, the protoplanetary disk should be relatively equal, but as the system moves, the planets form and remove the inner part of the disk.
"When we look at smaller atrial discs, such as protoplanetary disks, which are at an earlier stage of evolution, when planets form, or before planets form, they emit a lot of gas and dust in places where we find these holes in old debris," he said. "Something removed this material over time, and one way to do that is with planets."
Because the polarized light from the discs of debris can theoretically teach astronomers the composition of dust, the Postman hopes to refine the models in order to pre-determine the composition, particularly for water identification, which is likely to be a condition of life.
Studies like this could help answer the important question about our solar system, Callas said.
"If you play the clock of your own solar system for 4.5 billion years, which one was from that disk? Were we in a narrow circle?" He said.
Astronomers are taking rare pictures of the planets forming the planet around the stars
Thomas M. Esposito et al, Debris Disk Results from Gemini Planet Imager Exoplanet Survey's Polarimetric Image Campaign, Astronomical Journal (2020). DOI: 10.3847 / 1538-3881 / ab9199
Rogue Gallery of Dusty Star Systems Displays Exoplanet Nurseries (June 24, 2020)
Found on June 25, 2020
This document is subject to copyright. Except for any fair case for the purposes of private law and research
Transfer of part is possible without written permission. Content is provided for informational purposes only.