- uploaded: Nov 12, 2011
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The Hubble Space Telescope has turned up a population of tiny, young galaxies that are just brimming with starbirth. The 69 dwarf galaxies were spotted during a three-year sky scan known as the Cosmic Assembly Deep Extragalactic Legacy Survey, or CANDELS. Their average mass is only about 1 percent the mass of our own Milky Way galaxy, but they're churning out stars at such a furious pace that the stars are on track to double in just 10 million years. It would take the Milky Way 10 billion years to achieve a similar doubling. The galaxies are being seen as they existed 9 billion years ago, during a time when the star production rate was higher than it is today. But even by that measure, the birth rate is so high that astronomers may have to reassess their models for galaxy formation. Astronomers could spot the galaxies because the radiation from hot, young stars lit up the oxygen in the gas surrounding them like a neon sign. Or at least that's the way it's described in today's image advisory from NASA. "The galaxies have been there all along, but up until recently astronomers have been able only to survey tiny patches of sky at the sensitivities necessary to detect them," said Arjen van der Wel of Germany's Max Planck Institute for Astronomy, lead author of a paper on the results being published online Nov. 14 in The Astrophysical Journal. "We weren't looking specifically for these galaxies, but they stood out because of their unusual colors." A co-author of the paper ...