Stellar streams are narrow bands of stars and gas that traverse the space surrounding the Milky Way. Recently, scientists discovered another 87 objects in the data from the Gaia space telescope that may turn out to be them.
What are stellar streams?
A new algorithm developed at the University of Michigan has helped scientists identify 87 new candidates for stellar streams. Although the first of these structures were discovered several decades ago, they still remain a mystery to astronomers.
And the reason is that they are narrow bands of stars and gas stretching hundreds of thousands of light-years beyond the Milky Way. Some of them are the remnants of dwarf galaxies and globular clusters broken apart by the gravity of our star system.
The rest are manifestations of the presence of dark matter. Its gravitational pull causes stars to cluster together and align in a line. However, scientists believe that there should be at least a third type of stellar stream that leaves behind star clusters that still exist today. And therefore, the number of these structures should actually be much higher.
87 new stellar streams
And now scientists have announced the discovery of 87 more previously unknown stellar streams. The source of information about them was a dataset from the Gaia space telescope. This instrument has collected a vast amount of data, but its original purpose was not to study faint cosmic structures.
That is precisely why these new streams are currently considered only as candidates. It is possible that some of them are actually just noise pollution. However, Gaia’s data at least tells other instruments where to look.
According to phys.org
