Post-common-envelope binary 照片檔

Researchers at the Universities of Warwick and Colorado Boulder have directly observed, for the first time, four white dwarfs stars orbiting in double star systems. The four systems all have larger and brighter companion stars called red dwarfs, making it look like these were single star systems. The new results have identified that each of these nearby red dwarfs were hosting a hidden white dwarf companion star (right). Towards the end of the life of a Sun-like star, it expands to dozens or hundreds of times its original size and pushes off its outer layers to leave behind its core - a white dwarf. If the original Sun-like star was in orbit around a red dwarf, its eventual expansion envelops both stars so that they share the same atmosphere. Once the envelope dissipates, the resultant red-dwarf/white-dwarf system is called a post-common-envelope binary (PCE binary)