It appears that the Milky Way had a “river of stars” hidden all along. The stars have been observed before, but scientists did not realise that the stars belong to one single stream. It appears that the cluster formed one billion years ago.
There are four long circles located around the edge of the Milky Way. The river of stars does move, and at the moment it is 330 light years away from Earth, which isn’t that far. The stream is 160 light-years wide and 1,300 light-years long.
“Identifying nearby disk streams is like looking for the proverbial needle in a haystack. Astronomers have been looking at, and through, this new stream for a long time, as it covers most of the night sky, but only now realize it is there, and it is huge, and shockingly close to the sun,” João Alves, the second author of the paper declared. Alves is an astronomer at the University of Vienna.
Studying stellar streams
This stellar stream is not something unique, and there are many such “rivers”. However, it is very tricky to observe them, as they are often hidden amidst the stars that surround them. Usually, streams are also located far away from Earth. “Finding things close to home is very useful, it means they are not too faint nor too blurred for further detailed exploration, [an] astronomer’s dream,” Alves said.
Researchers believe that star clusters which turn into such streams, can also offer them answers to other questions. For instance, analysing the stream could help scientists understand how galaxies receive their stars. However, when it comes to big galaxies such as the Milky Way, the star clusters are usually shredded and stars are pulled in various directions.