‘Vampire Stars’ More Common Than Thought
Most bright, massive stars have a companion star - in many cases with one a ‘vampire’ star sucking mass from the other, say astronomers using ESO’s Very Large Telescope (VLT).
Around three quarters of O-type stars have such a companion, and around a third of these pairs are expected ultimately to merge into a single star.
“These stars are absolute behemoths,” says Hugues Sana of the University of Amsterdam.
“They have 15 or more times the mass of our sun and can be up to a million times brighter. These stars are so hot that they shine with a brilliant blue-white light and have surface temperatures over 30,000 degrees Celsius.”
The astronomers studied a sample of 71 O-type single stars and members of binaries in six nearby young star clusters in the Milky Way. By analysing their light, they found that 75 percent of all O-type stars exist as part of binary systems, a higher proportion than previously thought.
More importantly, though, they found that far more of these pairs than thought are close enough to interact - through stellar mergers or transfer of mass - with profound implications for our understanding of galaxy evolution.