Largest known planet discovered

gas giant: The new planet — TrES-4 — is 70 per cent larger than Jupiter (left)

Cape Canaveral (Florida): An international team of astronomers has discovered the largest known planet orbiting another star.
The "transiting" planet — meaning one that passes in front of its parent star as seen from Earth — is about 70 per cent larger than Jupiter.
But the presumed "gas giant" has a much lower mass than Jupiter — the biggest planet in our Solar System — making it of extremely low density.
The new exoplanet, called TrES-4, is located in the constellation of Hercules and was discovered by a team working on the Transatlantic Exoplanet Survey (TrES).
TrES-4 circles the star GSC02620-00648, which lies about 1,435 light-years away from Earth. Being only about 7 million km from its parent star, the planet is also very hot, about 1,327°C.
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 lead author Georgi Mandushev, from the Lowell Observatory in Flagstaff, US.
Surprising size
It is so big, in fact, that its size is difficult to explain using current theories about superheated giant planets.
"We continue to be surprised by how relatively large these giant planets can be," says Francis O'Donovan, a graduate student in astronomy at the California Institute of Technology which operates one of the TrES telescopes. — Agencies