|Animation of a contact binary star. This system contains two stars that are so close together that they share matter and energy at their closest point. This makes the stars' surface temperatures very similar, despite their differing masses. When viewed from Earth, they are almost always seen as eclipsing binary variable stars, as the stars obstruct part of the system's light when they pass in front of each other. A contact binary star's period is linked to its temperature, with hotter pairs having longer orbital periods.
|Science Photo Library