A Search for Companions to Nearby Brown Dwarfs: The Binary DENIS-P J1228.2-1547
E. L. Martín,
1
W. Brandner,
2
G. Basri
1
Hubble Space Telescope imaging observations of two nearby brown
dwarfs, DENIS-P J1228.2-1547 and Kelu 1, made with the near-infrared camera and multiobject spectrometer (NICMOS), show that the DENIS object is resolved into two components of nearly equal brightness with
a projected separation of 0.275 arc second (5 astronomical units for a
distance of 18 parsecs). This binary system will be able to provide the
first dynamical measurement of 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 aged 0.5 × 109
years, which would have been detected at a separation larger than about
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.
1 Department of Astronomy, University of
California, Berkeley, CA 94720, USA.
2 Jet
Propulsion Laboratory/Infrared Processing and Analysis Center, Mail
Code 100-22, Pasadena, CA 91125, USA.
