Washington, Nov 11 : Astronomers have discovered a star which is more like the sun than any other observed till now. The star, HIP 56948, is located 200 light years away in the constellation Draco (the Dragon) and is being referred to as the Sun's 'twin' by astronomers, though probably being a billion years older than the Sun.

The new star has been discovered by the University of Texas at Austin using the 2.7-meter Harlan J. Smith Telescope at McDonald Observatory.

Before this finding, only three solar twins had been identified. They were 18 Scorpii, HD 98618 and HIP 100963.

But while they were all like the Sun in many ways, there was one major difference. They all contained several times more lithium than the sun.

This scenario made astronomers think that maybe the sun was unique with its low amount of lithium.

But the discovery of HIP 56948 with the same amount of lithium as the Sun has put that question to rest. It also suggests that the Sun¹s chemical composition is not unique, as previously thought by some scientists.

In fact, further studies based on the new finding has turned up another solar twin, HIP 73815, that contains a similarly low amount of lithium.

The detection of the new solar twin has also made scientists ponder over the possibility of the existence of life in such star systems.

According to astronomer Bill Cochran, who led the McDonald Observatory Planet Search, the chances of HIP 56948 having planets that host some type of life forms is bright. "For one, HIP 56948, like our sun, does not host any 'hot Jupiter' planets," he said. "Such planets are massive, short-period and orbit close to their parent stars, so common among the more than 200 stars found to date that host one or more planets," he added.

That is the reason why Jorge Melendez and Ivan Ramirez, Peruvian astronomers who discovered the twin, suggest that stars like HIP 56948 would be good targets for SETI (Search for Extra-Terrestrial Intelligence) researchers.

Searches for 'solar twins' are important because astronomers use the Sun as a baseline for many other types of studies.
The solar twins discovered at McDonald will be useful for many areas of astrophysics as well. In particular, they will help astronomers who study the chemical compositions of stars, as well as validate theoretical models of stars' interiors, and theoretical models of stellar evolution. (ANI)