London, Dec 16 : A team of astronomers have reported that a new camera is giving them the sensitivity they need to spot habitable extrasolar planets, which are nearly as small as Earth.

According to a report in Nature News, the team observed a planet - WASP-10b, which is around three times the mass of Jupiter orbiting the star WASP-10.

The team determined that the star is about 300 light years from Earth, and measured precisely how much the star dimmed as the planet passed in front of it.

A team led by John Johnson, an astronomer at the University of Hawaii in Honolulu, report that they were able to detect a dimming of less than 0.05 percent during a single transit of 2.2 hours.

In the process, they were able to both prove their technology and revise downwards the planet's radius to about that of Jupiter - 16 percent lower than previous estimates.

"This instrument provides us with the first realistic chance to detect a transiting Earth-like planet," said Johnson. "In the past, you'd have to spend maybe 10 nights on the telescope to get this precision, but now we are doing it in a single night," he added.

David Charbonneau of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, calls the quality of the new data "exquisite".

"Other methods typically give you information about the planet's orbit and mass," said Johnson.

"But, they don't give you information about the planet's interior structure. By measuring these transits to very high precision, we were able to actually infer that it has a core surrounded by a gaseous atmosphere," he added.

An estimated 30 percent of stars that resemble the Sun are thought to harbour super-Earths - planets larger than the Earth but smaller than a gas giant.

But at the moment, only 50 of roughly 330 detected extrasolar planets are known to transit their stars along our line of sight.

More data on planetary radii should be forthcoming thanks to OPTIC II, a more advanced version of the current camera which is expected to be up and running in about a year. (ANI)