Our own Sun is a pretty medium-sized star compared to what’s out there— or at least it used to be sort of medium sized, when we thought we knew the limits of how a star can get. A recently discovered group of colossal stars has changed all that, with the heaviest at 300 times the mass of the Sun, over twice as big as we had thought stars could get.
From the time of their birth, these massive stars produce outflows, such as powerful winds, which eventually reduce their mass, researchers said.
“Unlike humans, these stars are born heavy and lose weight as they age,” Crowther said. “Being a little over a million years old, the most extreme star R136a1 is already ‘middle-aged’ and has undergone an intense weight loss program, shedding a fifth of its initial mass over that time, or more than 50 solar masses.”
The stars are still, however, intensely bright.
For example, if the star R136a1 were to replace the sun in our solar system, it would outshine our closest star by as much as the sun currently outshines the full moon, and its powerful radiation would effectively sterilize our home planet.
“Its high mass would reduce the length of the Earth’s year to three weeks, and it would bathe the Earth in incredibly intense ultraviolet radiation, rendering life on our planet impossible,” said Raphael Hirschi, a research team member from Keele University in Staffordshire, England.