A huge ball of brightly burning gas drifting through a neighbuoring galaxy may be the heaviest star ever discovered -- hundreds of times more massive than the sun.
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 at 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.
Crowther said the giant was identified at the center of a star cluster in the Tarantula Nebula, a sprawling cloud of gas and dust in the Large Magellanic Cloud, a galaxy about 165,000 light-years away from our own Milky Way.
The star was the most massive of several giants identified by Crowther and his team .
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 the Earth's sun and they're brighter and hotter, too.
Surface temperatures can surpass 40,000 degrees Celsius (72,000 degrees Fahrenheit), seven times hotter than the sun. They're also several million times brighter, because the greedy giants tear through their energy reserves far faster than their smaller counterparts.
That also means that massive stars live fast and die young, quickly shedding huge amounts of material and burning themselves out in what are thought to be spectacular explosions.
"The biggest live only 3 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.