How do astronomers explain the existence of blue stragglers?

1 Answer
Jul 20, 2016

Blue stragglers are thought to be the result of collisions.

Explanation:

Blue stragglers are large stars in open or globular clusters which don't fit the pattern of the other stars. A blue straggler has more than double the expected mass for stars in the cluster.

The leading theory is that a blue straggler is caused by a collision between two stars or a star and some other equally massive object. This could be a close binary star system where the stars collide. Also, blue stragglers tend to occur in densely packed regions where stars are close together and can easily collide.