Astronomers Discover a New Born "Hot Jupiter" Being Torn Away by a Young Star 1,100 Light Years Away from Earth
A team of Astronomers led by Rice University has detected what appears to be a new born "hot Jupiter" that has its surface being torn away by the gravity of the star its orbiting every 11 hours.
The possible giant exoplanet, dubbed as PTFO8-8695 b, is at most twice the size of Jupiter orbiting the star PTFO8-8695 in the constellation Orion about 1,100 light years away from Earth. It was first identified as a candidate planet in 2012 by the Palomar Transit Factory's Orion survey using the transit method.
Transit method is a technique used by astronomers to determine both the presence and approximate of the planet based on how much the star dims when the planet pass between the star and the Earth's line of sight.
However, transit method can be difficult in terms of finding planets around young star. Existing telescopes can't provide enough view of the surface details due to the insufficient brightness of young stars. Also, visual outbursts and dimmings, strong magnetic fields and enormous starspots of active young stars can make it look like a planet exists where it does not.
For their present study, published in the Astrophysical Journal, researchers conducted a spectroscopic analysis of the light coming from the star. The researchers discovered that excess emission in the H-alpha spectral line coming from two components. The first component matches the very small motion of a star, while the other component seems to orbit it.
While the transit method revealed that the possible planet is only three to four percent the size of its star, H-alpha emission shows that the planet is as bright as the star.
In a statement, researchers explained that the gas has to be filling a much larger region where the gravity of the planet is no longer strong enough to hold on to it to produce such effect. When this occurs, the star's gravity will start to overwhelm the gravity of the planet and eventually suck the gas from the planet.
The team of researchers observed the PTFO8-8695 several times from the University of Texas at Austin's McDonald Observatory near Fort Davis, Texas, and the Kitt Peak National Observatory 4-meter telescope in southern Arizona.