A huge ball of brightly burning gas drifting through a neighbouring galaxy may be the heaviest star ever discovered — hundreds of times more massive than the Sun, scientists said on Wednesday after working out its weight for the first time. Those behind the find say the star, called R136a1, may once have weighed as much as 320 solar masses. Astrophysicist Paul Crowther said the obese star — twice as heavy as any previously discovered — has already slimmed down considerably over its lifetime. In fact it’s burning itself off with such intensity that it shines with nearly 10 million times the luminosity of the Sun. “Unlike humans, these stars are born heavy and lose weight as they age,” said Crowther, an astrophysicist at the University of Sheffield in northern England.
“R136a1 is already middle-aged and has undergone an intense weight loss programme.”Crowther said the giant was identified at the centre of a star cluster in the Tarantula Nebula, a sprawling cloud of gas and dust drifting through one of the Milky Way’s neighbouring galaxies. The star was the most massive of several giants identified by Crowther and his team in an article in the Monthly Notices of the Royal Astronomical Society.
While other stars can be larger, notably the swollen crimson-coloured ones known as red giants, they weigh far less. Still, the mass of R136a1 and its ilk means they’re tens of times bigger than our Sun, and that they’re brighter and hotter, too. Surface temperatures can surpass 40,000 degrees Celsius, seven times hotter than the Sun. They’re also several million times brighter, a product of the fact that the greedy giants tear through their energy reserves far faster than their smaller counterparts.