A binary star is a star system consisting of two stars orbiting around their common center of mass. The brighter star is called the primary and the other is its companion star, comes, or secondary. Binary stars work similar to planets revolving around the sun because they revolve around another star. Just like our sun is the center of gravity in our solar system, a binary star will revolve around the center of gravity that is shared with the other star. The image shows how the stars revolve when the opposite star is of the same mass. However if the stars have different masses they would still move in a circular manner but the point of which they revolve around would be different because the center of gravity would change.
What is a Binary Star
Binary stars are a star system consisting of two stars orbiting around their common center of mass. The brighter star is called the primary and the other is its companion star, comes, or secondary. This is often a "White Dwarf" consuming excess energy from a "Red Giant."