X-rays indicate that the collision of young planets may explain the darkening of the star – Astronomy Now

The Chandra X-ray observatory, studying the high-energy radiation of a star that darkens and brightens periodically, has found evidence suggesting the catastrophic collision of two infantile planets, producing a huge cloud of debris, including significant amounts of iron, which would explain the most recent change in star intensity.

The star, known as RW Aur A, is located in the Taurus-Auriga constellation 450 light-years from Earth. outbreak in stellar nurseries. RW Aur has faded every few dozen years and then anime again, causing speculation about the effects of dusty clouds of debris in orbit around the star, or other unfamiliar processes taking place closer.

The most recent graduation of RW Aur A has obtained spectra showing significant amounts of iron in starlight, indicating the possible collision of two young planets

"Computer simulations have long predicted that the planets can fall into a young star, "said Hans Moritz Guenther, a researcher at the Kavli Institute of Astrophysics and Space Research at MIT, who led the study." If our interpretation data is correct, this would be the first time we would directly observe a young star devouring a planet or planets. "

Previous star dimming events may have been caused by similar body collisions of planetary size. "

" It's a speculation, but if you have a two-piece collision, it's possible that they'll then be on dirty orbits, which increases the probability. " they are touching something else again. Guenther says.

Astronomers have noted the changes in brilliance of RW Aur A since 1937. Graduation events usually last about a month, although they have lasted longer in recent years. RW Aur A further decreased in January 2017 and this time, the Guenther team studied the event with Chandra

"The X-rays come from the star, and the specter of X-rays change as the rays pass through the gas in the disc, "says Guenther. "We are looking for some X-ray signatures that gas leaves in the X-ray spectrum."

Chandra recorded nearly 14 hours of radiographic data. The data indicates that the star is much hotter than expected and has a large amount of debris in a surrounding disk. He also revealed an unusual amount of iron in the disc.

"Here we see a lot more iron, at least 10 times more than before, which is very unusual, because typically hot, active stars have less iron than others, whereas this one has more, "says Guenther." Where does all this iron come from? "

There are at least two possibilities.One is a phenomenon known as a pressure trap of dust, in which small particles can be trapped in so-called "dead" areas in a planetary disk and then released later due to gravitational interactions, falling into the star and releasing the radiation seen by Chandra [19659003] The other theory, the one favored by Guenther's team, is that two planetesimals collided in. If one or the other of these condemned worlds were made in part of iron, the collision could release large amounts of iron-rich debris that could obscure the light from RW Aur A diving into the star.

"Guenther, MIT colleagues David Huenemoerder and David Principe, as well as researchers at the Harvard-Smithsonian Center for Astrophysics and collaborators in the young stars, but these two scenarios could do something that looks like what Germany and Belgium have co-authored an article describing the observations in Astrophysical Journal