Scientists are excited about a newly discovered star that lives right in our own Milky Way galaxy. The reason for the excitement is that the star is tiny and is about 13.5 billion years old. The star is known as 2MASS J18082002–5104378 B, and one of its key features is a very low metal count.
Scientists say that in the early universe there were no metals. Metals that are abundant today are believed to have been created in the hearts of these early stars and then flung into the universe as these ancient stars died out. This means the younger the star is, the more metals it has inside. 2MASS J18082002–5104378 B has the lowest metal count of any star ever discovered at about 10% of the metallicity of Earth.
This discovery could mean that the Milky Way is much older than the 8-10 billion year estimate scientists use today. This newly discovered star is also very small at about 10% of the mass of the sun, which puts it on the lower limit for the ability to burn hydrogen. This discovery is at odds with notions of ancient stars. Many scientists believed that the first stars were massive and died out long ago.
2MASS J18082002–5104378 B is so small and dim that it remained undetected until now, and its discovery was because it is part of a binary pair. The tiny star was discovered while studying its more massive partner star. Scientists say that a star as small as 2MASS J18082002–5104378 B could live for trillions of years.
The discovery of this very small and faint star has scientists wondering how many other ancient and dim stars are still out there waiting to be discovered. Scientists say that the discovery of a star like this is as rare as finding a needle among an acre of haystacks.
SOURCE: Astrophysics Journal