Scientists believe episodes of shimmering light 450 light years away from Earth are actually a destructive star “devouring” parts of an alien planet.
Fluctuating light levels around a young star known as RW Aur A have puzzled astronomers for decades, with the celestial body appearing to dim before brightening again.
But using NASA’s powerful Chandra X-ray telescope, a group of scientists might just have cracked the secret behind the mysterious luminescence.
According to the researchers, led by academics at the Massachusetts Institute of Technology, the light is from a planet or planets falling into the star’s burning aura. The theory is that debris from the collisions has generated a veil of dust and gas thus providing a cloud that occasionally dims the star RW Aur A.
“Computer simulations have long predicted that planets can fall into a young star, but we have never before observed that,” MIT scientist Hans Moritz Guenther, who was part of the study, said.
“If our interpretation of the data is correct, this would be the first time that we directly observed a young star devouring a planet or planets.”
#News: Chandra data indicates that a young star has likely destroyed and consumed an infant planet! If so, this would be the first time that scientists have witnessed such an event! More about the discovery: https://t.co/lhoNgQonKs pic.twitter.com/TmNtGtnH3B
— Chandra Observatory (@chandraxray) July 18, 2018
Located in a cloudy region known as the Taurus Auriga, RW Aur A is thought to be several million years old. NASA estimates that the dimming of the star lasts for approximately one month at a time, the latest period observed by the Chandra observatory during 2017.
“Much effort currently goes into learning about exoplanets and how they form, so it is obviously very important to see how young planets could be destroyed in interactions with their host stars and other young planets, and what factors determine if they survive,” Guenther added.
Scientists have long thought that exoplanets—planets beyond the solar system—were restricted to the confines of our Milky Way. After all, our galaxy is a warped disc about a hundred thousand light-years across and a thousand light-years thick, so it’s incredibly difficult to see beyond that.
But now, a new study is saying there could be extragalactic exoplanets.
The study, published in The Astrophysical Journal Letters, gives the first evidence that more than a trillion exoplanets could exist beyond the Milky Way.
Using information from NASA’s Chandra X-ray Observatory and a planet detection technique called microlensing to study a distant quasar galaxy , scientists at the University of Oklahoma found evidence that there are approximately 2,000 extragalactic planets for every one star beyond the Milky Way.
Some of these exoplanets are as (relatively) small as the Moon, while others are as massive as Jupiter. Unlike Earth, most of the exoplanets are not tightly bound to stars, so they’re actually wandering through space or loosely orbiting between stars.
“We can estimate that the number of planets in this [faraway] galaxy is more than a trillion,” says Xinyu Dai, the astronomy and astrophysics professor who led the study.
Microlensing works like magnification, says co-author Eduardo Guerras. It’s a highly nuanced process that looks at frequencies emitted by moving celestial objects, meant to observe how they distort and magnify light that comes in from the objects near them. This light then illuminates things that aren’t otherwise visible.
“This microlensing is amplifying something that is very small and changing colors, which makes no sense,” Guerras says, “or it’s amplifying a small region of a bigger object and that object has different colors.”
Since these objects are so distant—the extragalactic bodies are some 3.8 billion years away—microlensing is the only way to get a sense of their shape. The researchers know they’re looking at planets because of the speed at which they’re moving.
“You can have this effect with stars, but it would be much, much less likely. It would be way less frequent,” Guerras says. “If you have only one planet, the chances of observing it twice is astronomically small.”
Considering scale, detecting exoplanets can be tricky. Directly viewing exoplanets within the Milky Way is nearly impossible, so astrophysicists have to sift through data and use other detection techniques that give way to evidence of planet signatures. Normally, it takes multiple methods to confirm if there is actually an exoplanet out there, and in some cases, detections have turned out to be false positives.
“These stars are really far away. There’s no way you can observe them by any [traditional] means,” Guerras says.
The researchers are hoping that with the publication of their study, other scientists will pick up the data and develop another technique to verify whether or not these extragalactic planets exist.
“We hope other teams publish independent analyses to confirm our findings,” Dai says. “I think this is a case where scientific discoveries can be triggered by the spark of ideas.”
Mr Americana, Overpasses News Desk
July 19th, 2018