About Binary Star System:
- A binary star is a system of two gravitationally bound stars that orbit a common center of mass called a
- Stars in a binary system do not necessarily have the same mass, size, or brightness.
- The larger star of a binary couple is called the primary star, while the smaller one is known as the secondary star or the companion star.
- Binary stars are double stars, but not all double stars are binary stars.
- This is because some double stars comprise two stars close enough in the sky over Earth to appear as a single point of light, but they are actually vastly separated in space and not part of a gravitationally bound binary system–these are called optical doubles.
- Unlike the sun, the vast majority of stars have a binary partner. It is estimated that around 85% of stars exist in binary star systems or systems with three or more stars.
- Binary star systems can also include systems containing a normal star and a stellar remnant, an object that forms when a star runs out of the fuel for nuclear fusion and collapses under its own gravity.
- These dense and compact star "corpses" can include white dwarfs, neutron stars, and black holes.
- Especially ancient binary systems can contain two stellar remnants orbiting each other.
- In some binary systems, the stars are so close together that they exchange material. This mass transfer occurs when the radius of one star is not much smaller than the orbital separation between the stars.
