THERE is a monstrous star, perhaps 40 million times as bright as the sun, near the middle of our galaxy. It is the most luminous star ever discovered.
Steve Eikenberry, of the University of Florida at Gainesville, and his colleagues announced the discovery last week at a meeting of the American Astronomical Society in Atlanta, Georgia. The star, called LBV 1806-20, had been spotted before, but interstellar dust clouds obscured its true brilliance until Eikenberry and his team pinned down the star鈥檚 distance and temperature, as well as how much of its light is being absorbed. Using data from several telescopes, they worked out that the star behind the veil of dust is between 5 and 40 million times as luminous as the sun.
That means it must be at least 150 times the sun鈥檚 mass 鈥� impossibly big, according to standard theory. Before it reached this mass, the growing star should have got so bright that its radiation would have blown away any surrounding gas, stopping its growth short. But LBV 1806-20 has other overweight companions. 鈥淚t鈥檚 an entire cluster of freakishly massive stars,鈥� says Eikenberry.
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The answer may lie nearby. A rare kind of neutron star just a few light years from LBV 1806-20 is the remnant of a supernova explosion that went off 1 or 2 million years ago. Shock waves from this explosion may have squeezed gas in the surrounding nebula so violently that the young star couldn鈥檛 blow it away.