HE0107-5240

HE0107-5240 is a Population II star that has almost no metal. This kind of star is called a metal-poor star. It is close to  away from Earth. It is one of the most metal-poor stars known in our galaxy, with a metallicity of -5.2; This means it has just  of the metal that the Sun has. Because of its very low metallicity, it is believed to be one of the earliest Population II stars to have formed. If so, then it is also very old, with an age of roughly 13 billion years. Because the star still has a bit of metal, it does not belong to the first generation of stars (the hypothetical Population III). These stars changed the pure hydrogen, helium, and lithium formed by the Big Bang into heavier elements, such as carbon, oxygen, and metals.

The star is small for a star that formed in the early universe. This explains why it is so old, as bigger stars die more quickly. To help explain why this star is so small, people think it was once part of a binary system. 

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Category:Stars