Discovery of a Young Planetary-Mass Binary
Ray Jayawardhana1* and
Valentin D. Ivanov2
We have identified a companion to the young planetary-mass brown
dwarf Oph 162225-240515. This pair forms a resolved binary consisting
of two objects with masses comparable to those of extrasolar
giant planets. Several lines of evidence confirm the coevality
and youth of the two objects, suggesting that they form a physical
binary. Models yield masses of
14 and
7 times the mass of Jupiter
for the primary and the secondary object, respectively, at an
age of
1 million years. A wide (
240–astronomical unit)
binary in the ultra-low-mass regime poses a challenge to some
popular models of brown dwarf formation.
2 European Southern Observatory, Avenida Alonso de Cordova 3107, Vitacura, Santiago 19001, Chile.
* To whom correspondence should be addressed. E-mail: rayjay{at}astro.utoronto.ca
