Hubble dissects nest of monster stars

SHEFFIELD, England, March 17 (UPI) -- For the first time, astronomers captured ultraviolet imagery of the young star cluster R136, home to dozens of massive, bright and hot stars.

The ultraviolet survey was made possible by the Hubble Space Telescope's Wide Field Camera 3 and Space Telescope Imaging Spectrograph.

"The ability to distinguish ultraviolet light from such an exceptionally crowded region into its component parts, resolving the signatures of individual stars, was only made possible with the instruments aboard Hubble," Paul Crowther, an astronomer from the University of Sheffield, in England, explained in a news release. "Together with my colleagues, I would like to acknowledge the invaluable work done by astronauts during Hubble's last servicing mission: they restored STIS and put their own lives at risk for the sake of future science!"

The survey -- detailed in the journal Monthly Notices of the Royal Astronomical Society -- identified several dozen stars measuring more than 50 solar masses, as well as nine stars exceeding 100 times the mass of the sun. Four of the nine are at least 150 times the mass of the sun.

Currently, scientists don't have an explanation for why R136 hosts so many giant stars, but are hopeful future imaging efforts will offer answers.

"There have been suggestions that these monsters result from the merger of less extreme stars in close binary systems," said study co-author Saida Caballero-Nieves. "From what we know about the frequency of massive mergers, this scenario can't account for all the really massive stars that we see in R136, so it would appear that such stars can originate from the star formation process."