E-Paper
US lab discovers rocky planet
The new planet in Sagittarius constellation takes about a decade to circle its dwarf star.
A frigid planet five times the size of Earth was discovered by an international team of scientists on Wednesday, a US laboratory announced.
The new planet, dubbed OGLE-2005-BLG-290 Lb, is in the Sagittarius constellation, not far from the central bulge of Earth's galaxy, and takes about a decade to circle its dwarf star, the Lawrence Livermore National Laboratory announced.
A cool parent star and a large orbit imply that the planet's surface temperature is close to 249 degrees Celsius below zero.
The planet is likely to have a rocky surface covered by frozen seas.
"That fact that we stumbled on one means that there are thousands of them out there," said Kem Cook, an astronomer, who is a member of Probing Lensing Anomalies Network, which took part in the discovery.
"It has a solid core. Its mass is low enough that it couldn't hold itself together if it were just gas."
Scientists using telescopes in Chile, Australia and South Africa deduced the planet's existence in July 2005 using a micro-lensing light-analysis technique based on an idea by Albert Einstein.
"Micro-lensing can tell us how common planets are in distant parts of the galaxy and probe details of planetary formation that other techniques cannot," Cook said.
