Are there any lonely stars between galaxies?
Yes, there are stars between galaxies. When there are collisions or interactions between galaxies, stars can be ripped out of the galaxies. These stars will then wander into space between galaxies. Such stars have been observed with the Hubble Space Telescope. Astronomers now need to determine how many of these stars may exist, in order to get a better estimate of how much matter there is in the Universe. (This is the press release that presents the discovery of such stars, and here is Astronomy Picture of the Day's take on the subject.)
This page updated on June 27, 2015