A Search for Companions to Nearby Brown Dwarfs: the Binary DENIS-P J1228.2-1547

Eduardo L. Martín, Wolfgang Brandner, Gibor Basri

1999, Science 283, 1718


Hubble Space Telescope near infrared camera and multiobject spectrometer (NICMOS) imaging observations of two nearby brown dwarfs, DENIS-P J1228.2-1547 and Kelu 1, show that the DENIS object is resolved into two components of nearly equal brightness with a projected separation of 0.275 arcsec (5 astronomical units for a distance of 18 parsecs). The binary system can provide the first dynamical measurement if the masses of two brown dwarfs in only a few years. Upper limits to the mass of any unseen companion in Kelu 1 yield a planet of 7 Jupiter masses and age 0.5 Gyr, that would have been detected at a separation larger than 4 astronomical units. This example demonstrates that giant planets could be detected by direct imaging if they exist in Jupiter-like orbits around nearby young brown dwarfs.

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