Scientists spot heaviest star,say it’s losing weight with time

“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-colored 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 giants tear through their energy reserves much faster than their smaller counterparts.

“The biggest live only three million years,” Crowther said. “In astronomy that’s a very short time.”

Small lifespans are one of several reasons why these obese stars are so hard to find. Another is that they’re extremely rare,forming only in the densest star clusters.

Crowther’s team re-examined previously known stars to find an accurate measurement of their weight. The team reviewed archival data from the Hubble Space Telescope and gathered readings from the European Southern Observatory’s Very Large Telescope at Paranal in Chile.

Scientists who weren’t involved in the find said the results were impressive. “What they’re characterising as a single massive star could in fact be a binary system too close to be resolved,” said Mark Krumholz,an astronomer at the University of California,Santa Cruz.