The animation depicts X-ray stars, supernova remnants, active galactic nuclei, and quasars on a map of the entire sky, using the plane of our galaxy as the center line. Most of the X-ray stars and other objects are pinpoints, just like visible stars. But to better illustrate variations in brightness, the animation shows these objects as colored circles. Larger circles represent brighter objects. The color of the circle is the "X-ray color:" Blue generally represents higher-temperature gases and red represents lower-temperature gases.
This clip depicts the x-ray sky from April 30, 1999 through June 30, 1999. In this excerpt, a black hole on the left varies both in the X-ray wavelengths it emits (temperature) and in its brightness. The two neutron star binary systems on the right also exhibit variation in their brightness and energy as the neutron stars and their companion stars (not visible in this animation) orbit each other. Most of the activity lies along the galactic plane.