News Release Archive:

News Release 376 of 953

March 15, 2006 01:00 PM (EST)

News Release Number: STScI-2006-11

Astronomers Measure Precise Mass of a Binary Brown Dwarf

March 15, 2006: This is an artist's concept of a pair of eclipsing brown dwarfs. Brown dwarfs are mysterious celestial objects that fall somewhere between the smallest stars and the largest planets. They have always been viewed by astronomers as a critical link in the understanding of how both stars and planets form. One problem has been that brown dwarfs are hard to find and so have defied nearly all attempts to accurately assess their size. But now astronomers, have discovered a pair of young brown dwarfs in mutual orbit. This has enabled scientists to weigh and measure the diameters of brown dwarfs for the first time. The new observations confirm the theoretical prediction that brown dwarfs start out as star-sized objects, but shrink and cool and become increasingly planet sized as they age. Before now, the only brown dwarf whose mass had been directly measured was much older and dimmer.

See the rest:

Credit (Artwork): NASA, ESA, and A. Feild (STScI)

Credit (Science): NASA, NSF, J. Valenti (STScI), K. Stassun (Vanderbilt University), and R. Mathieu (University of Wisconsin-Madison)