From BBC, by Jonathan Amos
They are among the true monsters of space – colossal stars whose size and brightness go well beyond what many scientists thought was even possible.
One of the objects, known simply as R136a1, is the most massive ever found.
Viewed today, the star has a mass about 265 times that of our own Sun; but the latest modelling work suggests at birth it could have been bigger, still.
Perhaps as much as 320 times that of the Sun, says Professor Paul Crowther from Sheffield University, UK.
“If it replaced the Sun in our Solar System, it would outshine [it] by as much as the Sun currently outshines the full Moon,” the astronomer told BBC News.
The stars were identified by Crowther’s team using a combination of new observations on the Very Large Telescope facility in Chile and data gathered previously with the Hubble Space Telescope.
The group studied the NGC 3603 and RMC 136a clusters – regions of space where thick clouds of gas and dust are collapsing into even denser clumps.
In these places, huge stars ignite to burn brief but brilliant lives before exploding as supernovas to seed the Universe with heavy elements.
NGC 3603 is relatively close in cosmic terms – just 22,000 light-years distant. RMC 136a (more often nicknamed R136) is slightly further away, and is sited within one of our neighbouring galaxies, the Large Magellanic Cloud, some 165,000 light-years away.
The team found several stars with surface temperatures over 40,000 degrees – more than seven times hotter than our Sun.
The research shows these young stellar objects to be unbelievably bright, truly massive and also extremely wide – perhaps 30 times the radius of our Sun in the case of R136a1.
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