"Discovery: Smallest Star in Binary System with Ghostly Companion"

Astronomers have discovered an extraordinary binary star system, TMTS J0526, where a "dead star," or white dwarf, completes an orbit around its hot subdwarf companion in just 20.5 minutes, squeezing almost 72 years into one Earth day. This system, located 2,760 light-years away, is significant not only for its incredibly short orbital period but also for providing observational evidence for the formation of a tiny hot subdwarf via the ejection of a secondary common envelope. The discovery sheds light on the birth of such tiny subdwarf stars and the dynamics of binary star systems.