Binary stars are two stars that orbit a mutual center of gravity. It is the most common type of multistar system.

Binary star, pair of stars in orbit around their common center of gravity. A high proportion, perhaps one-half, of all stars in the Milky Way Galaxy are binaries or members of more complex multiple systems. Some binaries form a class of variable stars, the eclipsing variables.

Learn what binary stars are, how they are formed, and how they affect the evolution of stars. Find out the characteristics, periods, and eccentricities of different types of binary stars, and how they can be observed and weighed.

Binary Stars. The variety seen in double-star systems is nearly as rich as the galaxy’s stellar population as a whole. These pairs can differ significantly in mass, with, say, a mid-sized yellow star like our Sun locked in an orbital embrace with a far smaller, cooler red dwarf.

Learn about the definition, classification, discovery and evolution of binary stars, which are two stars that share a common center of mass. Find out how binary stars can affect the potential for life and the closest binary star system to our solar system.