The star, HIP 56948, is more similar to the Sun than any ever known. Located as far as 200 light-years away in the constellation Draco, the star is about a billion years younger than the Sun.
Previously, only three known solar twins, each of which is 18 Scorpii, HD 98 618, and HIP 100963. However, although in some respects are similar to the sun, three stars have fundamental differences in the content lithiumnya far beyond the content of lithium in the Sun. The content of lithium in the Sun is very little time to make the astronomers thought that the Sun is a very unique star among other stars.
The discovery of the sun is breaking new twin assumptions. HIP 56948 known to have the same low lithium content of the Sun. The study also revealed other twin of the Sun, HIP 73815, which also has the same low lithium content.
Questions about the uniqueness of the Sun is related to what is known as the "anthropic principle", the question of whether there is something special about the Sun that has allowed life to our solar system. This finding is not fully answer these questions, but they do show that the uniqueness of it is clearly not in its chemical composition.
Melendez 'and Ramirez' findings support the opposite of the anthropic principle, the so-called "Copernican" view, that it is possible that life can be found anywhere in the universe. They suggest that stars like HIP 56948 may be good targets for the researchers at the SETI program (Search for Extra-Terrestrial Intelligence).
The star has been studied by Planet Search Program at the McDonald Observatory, led by astronomer Bill Cochran of the University of Texas. His team found that, like our Sun, HIP 56 948 does not have a planet of the class of "hot Jupiter" - a large-mass planet, has a short orbital period, and circle around their parent stars in very close proximity. This type of planet known to be very common. Until now has been found more than 200 stars that have one or more of hot Jupiter-class planets that orbit.
Search for "solar twins" are important, because astronomers use the Sun as a benchmark in the various studies. However, they can not study the Sun in the same way as they learn a distant star, because it is too close and too bright.
The solar twins discovered at McDonald will be very useful in many areas of astrophysics. Among them, the stars can help astronomers who study the chemical composition of stars, as well as validate theoretical models of the interiors and stellar evolution.