AUDIO:
The typical X-ray sources are X-ray binaries in our galaxy. These
X-ray binaries are in fact two stars that rotate around each other.
One of the two is a normal star. But the other is an odd star, such
as a neutron star or black hole, which has about the same mass as
our Sun, but has shrunk to ten kilometers or less in radius.

VIDEO:
Video shows two stars orbiting each other. The odd star is pulling
matter away from the normal star.