Dead star smaller than Jupiter is one of the tiniest in the known universe
Astronomers have discovered an extraordinary binary system in which a "dead star," or white dwarf, whips around its blisteringly hot and tiny stellar companion so fast that it squeezes almost 72 years into just one Earth day. The system, designated TMTS J0526, was spotted by a Tsinghua University team using the Tsinghua University-Ma Huateng Telescope for Survey (TMTS) and is located around 2,760 light-years from Earth. TMTS J0526 contains a carbon- and oxygen-rich white dwarf star with a mass around 74% that of the sun's. It whips around a hot subdwarf star with a mass around a third of our star's, and is just around 7 times as wide as Earth, making it smaller than the gas giant planet Jupiter — and one of the smallest stars ever seen in terms of volume. The components of TMTS J0526 complete one orbit roughly every 20.5 minutes. This makes it a record-breaker for this type of binary, though the system is still a slouch...