News Release Archive:

News Release 345 of 1051

January 5, 2009 12:20 PM (EST)

News Release Number: STScI-2009-01

Brown Dwarfs Don't Hang Out With Stars


Image: Binary Brown Dwarf Kelu-1

Binary Brown Dwarf Kelu-1STScI-PRC2009-01a

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This pair of NASA Hubble Space Telescope images of the binary brown dwarf Kelu-1 trace the orbital motion of the two stars over a seven-year span as photographed by the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) on Hubble.

In 1998, the "stars" were too close together to be resolved by Hubble. By 2005, they had moved apart to a separation of 520 million miles. The projected maximum separation is 550 million miles.

Binary systems allow astronomers to estimate the mass of companion objects. The brown dwarfs are 61 and 50 times the mass of Jupiter. They are therefore too small to burn as stars, but too large to have formed as planets. Based on the total estimated mass of the system, astronomers suspect there is a third brown dwarf member that has not yet been resolved.

Object Names: Kelu-1 AB, Kelu

Image Type: Astronomical/Illustration

Credit: NASA, ESA, and M. Stumpf (Max-Planck-Institute for Astronomy)


The above montage includes these images:

Binary L Dwarf Kelu-1 (HST August 14, 1998) Image Type: Astronomical Binary L Dwarf Kelu-1 (HST August 14, 1998) Binary L Dwarf Kelu-1 (HST July 31, 2005) Image Type: Astronomical Binary L Dwarf Kelu-1 (HST July 31, 2005)

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