Direct imaging discovery of 12-14 Jupiter mass object orbiting a young binary system of very low-mass stars

TL;DR

This paper reports the direct imaging discovery of a 12-14 Jupiter mass object orbiting a young binary system of very low-mass stars, providing new insights into planetary formation around such stars.

Contribution

First direct imaging detection of a planetary-mass companion around a low-mass binary star system at a large separation.

Findings

Discovered a 12-14 MJup companion at 84 AU from a young binary system.

Confirmed proper motion and orbital motion consistent with a bound companion.

First imaged planet/brown dwarf boundary object around a binary system at such a separation.

Abstract

Context. Though only a handful of extrasolar planets have been discovered via direct imaging, each of these discoveries had tremendous impact on our understanding of planetary formation, stellar formation and cool atmosphere physics. Aims. Since many of these newly imaged giant planets orbit massive A or even B stars we investigated whether giant planets could be found orbiting low-mass stars at large separations. Methods. We have been conducting an adaptive optic imaging survey to search for planetary-mass companions of young M dwarfs of the solar neigbourhood, to probe different initial conditions of planetary formation. Results. We report here the direct imaging discovery of 2MASS J01033563-5515561(AB)b, a 12-14 MJup companion at a projected separation of 84 AU from a pair of young late M stars, with which it shares proper motion. We also detected a Keplerian-compatible orbital motion. Conclusions. This young L-type object at planet/brown dwarf mass boundary is the first ever imaged around a binary system at a separation compatible with formation in a disc.