Astronomers have spotted an extreme binary star system. It's closer, hotter and more massive than any double star ever observed.
The research team spotted the binary system, called VFTS 352, while scanning the Tarantula Nebula using the European Southern Observatory's Very Large Telescope. The double star is 160,000 light-years away.
The centers of the two stars are separated by roughly one million miles, completing their orbit around each other in less than a day. Together their mass is equal to 57 suns. Each star burns at a temperature of 40,000 degrees Celsius.
Unlike most binary systems, the two stars are equal in size. They don't steal but share their stellar material. Roughly 30 percent of their material now overlaps.
Researchers believe the stars' interiors are actually mixing together.
"The VFTS 352 is the best case yet found for a hot and massive double star that may show this kind of internal mixing," lead researcher Leonardo A. Almeida, an astronomer at the University of Sao Paulo in Brazil, said in a press release. "As such it's a fascinating and important discovery."