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>> |
|
news in brief
|
|
|
|
news links
|
|
Sunday, June 21
Revealing how and when a black hole’s mighty winds can squash star formation
Univ. of Michigan — 11:36 am ET (1536 GMT) How an oddball ‘hot Jupiter’ shows us new possibilities for planets beyond our solar system
Univ. of Michigan — 11:35 am ET (1535 GMT) GMV will develop Satellite Control System for CAMILA, Poland’s largest satellite initiative
GMV — 11:35 am ET (1535 GMT) Gilat to Acquire Comtech’s Satellite & Space Communications Segment Creating a Leading Provider of Advanced Defense and Satellite Communications Solutions
Gilat Satellite Networks — 11:33 am ET (1533 GMT) Stars of physics descend on Westminster to halt catastrophic funding cuts
Royal Aeronautical Society — 11:32 am ET (1532 GMT) |
