Free Astronomy Magazine November-December 2015

12 NOVEMBER-DECEMBER 2015 SPACE CHRONICLES orbit e a c h other in little more than a day. Both components are clas- sed as O-type stars. Such stars are typically between 15 and 80 times more massive than the Sun and can be up to a million times brighter. They are so hot that they shine with a brilliant blue-white light and have surface tempera- tures over 30,000 degrees Celsius. The centres of the stars are sepa- rated by just 12 million kilometres. In fact, the stars are so close that their surfaces overlap and a bridge has formed between them. T he double star system VFTS 352 is located about 160,000 light- years away in the Tarantula Nebula (the star’s name indi- cates that it was observed as part of the VLT FLAMES Tarantula Survey). This remarkable region is the most active nursery of new stars in the nearby Universe and new observations from ESO’s VLT have revealed that this pair of young stars is among the most extreme and strangest yet found. (This study also used brightness measure- ments of VFTS 352 over a period of twelve years made as part of the OGLE survey.) VFTS 352 is composed of two very hot, bright and massive stars that by ESO T his artist’s impression shows VFTS 352 — the hottest and most massive double star system to date where the two components are in contact and sharing material. The two stars in this extreme sys- tem lie about 160 000 light-years from Earth in the Large Magellanic Cloud. This intriguing system could be heading for a dramatic end, ei- ther with the formation of a single giant star or as a future binary black hole. [ESO/L. Calçada] VLT finds hottest and most massive touching double star