An international team of astronomers has discovered the largest known exoplanet planet orbiting another star, BBC reported.

The new exoplanet is located in the constellation of Hercules and was discovered by a team working on the Transatlantic Exoplanet Survey (TrES), whose lead author is the Bulgarian Georgi Mandushev from the Lowell Observatory in Flagstaff.

The "transiting" planet - meaning one that passes in front of its parent star as seen from Earth - is about 70% larger than Jupiter.

The planet, called TrES-4, is a giant ball made of mostly hydrogen that is 20 times larger than Earth and circling a star 1,400 light years away. It is so big that it is baffling scientists and so light that it could theoretically float on water.

But the presumed "gas giant" has a much lower mass than Jupiter making it of extremely low density.

TrES-4 circles the star GSC02620-00648. Being only 7 million kilometres from its parent star, its temperature is about 1,327 degrees Celsius.TrES-4 was discovered using three telescopes, two in Arizona, in the US, and one in the Canary Islands.

Because of the relatively weak pull exerted by TrES-4 on its upper atmosphere, some of the atmosphere probably escapes in a curved comet-like tail.

"TrES-4 is the largest known exoplanet," said Mandushev.

Mandushev from the Lowell Observatory in Arizona is the lead author of the paper announcing the discovery in the Astrophysics Journal. He says TrES-4 appears to be almost puffed up.

"It's a very enigmatic planet, I would say, because it's so big and has such a low density," he said. "At this point, theoretical models of planets cannot explain this one."

We need your support so Novinite.com can keep delivering news and information about Bulgaria! Thank you!