A brilliant star has been discovered in our neighboring galaxy, the Large Magellanic Cloud, but unlike other known superstars it is alone and not in a cluster.
VFTS 682 was discovered with the European Southern Observatory’s Very Large Telescope while surveying bright stars in and around the Tarantula Nebula.
Now an international team of astronomers has determined that the lone star is much brighter than previously realized. Clouds of dust prevented short wavelengths of green and blue light from being detected, giving the star a reddish appearance instead of its true blue-white luminosity.
VFTS 682 is one of the brightest known stars. It has a mass around 150 times that of our sun and is three million times brighter with a surface temperature of around 50,000 degrees Celsius compared with the sun’s surface temperature of 5,500 degrees.
Stars with these unusual properties have short lives, ending as a supernova with the potential for a long-duration gamma-ray burst, one of the brightest explosions in the universe. Previously, such stars have only been found inside packed clusters.
“We were very surprised to find such a massive star on its own, and not in a rich star cluster,” said lead author Joachim Bestenlehner at Armagh Observatory in Northern Ireland in a press release. “It’s origin is mysterious.”
The scientists found that the star is a near identical twin of one of the brightest superstars at the heart of the nearby R 136 star cluster, suggesting it could have been ejected from this cluster, but all known “runaway stars” are much smaller.
“It seems to be easier to form the biggest and brightest stars in rich star clusters,” said co-author Jorick Vink in the release. “And although it may be possible, it is harder to understand how these brilliant beacons could form on their own. This makes VFTS 682 a really fascinating object.”