Submitted on July 5, 2006
Accepted on July 24, 2006
Discovery of a Young Planetary Mass Binary
Ray Jayawardhana 1* and
Valentin D. Ivanov 2
1 Department of Astronomy and Astrophysics, University of Toronto, Toronto, ON M5S 3H8, Canada.
2 European Southern Observatory, Ave. Alonso de Cordova 3107, Vitacura, Santiago 19001, Chile.
* To whom correspondence should be addressed.
Ray Jayawardhana , E-mail: rayjay{at}astro.utoronto.ca
We report the discovery of a companion to a young planetary mass brown dwarf, Oph 162225-240515. This pair therefore forms a resolved binary consisting of two objects with masses comparable to those of extra-solar giant planets. The coevality of the two and several lines of evidence that confirm their youth suggest that they form a physical binary. Models yield masses of ~14 MJupiter and ~7 MJupiter, for the primary and the secondary respectively, at an age of ~1 million years. A wide (~240 AU) binary in the ultra-low-mass regime poses a challenge to some popular models of brown dwarf formation.
