Brown dwarfs heavier than expected
Posted: Thu, Jan 20, 2005, 7:43 AM ET (1243 GMT)
Brown dwarfs, objects intermediate in size between stars and planets, may be twice as heavy as predicted, a finding that could raise doubts about the discovery of some extrasolar planets. Astronomers used the European Southern Observatory's Very Large Telescope to observe a brown dwarf orbiting a young, nearby star. From the orbit, astronomers determined that the brown dwarf has a mass 88-98 times that of Jupiter, but with a temperature and luminosity consistent with an object half as massive, according to current models. Astronomers concluded that brown dwarf models underestimate the mass of such objects by a factor of two. This means that some objects previously identified as "free-floating" exoplanets — objects with the mass of planets but not bound to any star — may in fact be much heavier and thus could be considered brown dwarfs instead.
Brown dwarfs, objects intermediate in size between stars and planets, may be twice as heavy as predicted, a finding that could raise doubts about the discovery of some extrasolar planets. Astronomers used the European Southern Observatory's Very Large Telescope to observe a brown dwarf orbiting a young, nearby star. From the orbit, astronomers determined that the brown dwarf has a mass 88-98 times that of Jupiter, but with a temperature and luminosity consistent with an object half as massive, according to current models. Astronomers concluded that brown dwarf models underestimate the mass of such objects by a factor of two. This means that some objects previously identified as "free-floating" exoplanets — objects with the mass of planets but not bound to any star — may in fact be much heavier and thus could be considered brown dwarfs instead.| <<previous article | next article>> |
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