1205.0818 (Koraljka Muzic et al.)

Discovery of Two Very Wide Binaries with Ultracool Companions and a New Brown Dwarf at the L/T Transition    [PDF]

Koraljka Muzic, Jacqueline Radigan, Ray Jayawardhana, Valentin D. Ivanov, Jacqueline K. Faherty, Radostin G. Kurtev, Alejandro Nunez, Henri M. J. Boffin, Olivier Hainaut, Kelle Cruz, David Jones, Stanimir Metchev, Amy Tyndall, Jura Borissova

We present the discovery and spectroscopic follow-up of a nearby late-type L dwarf (2M0614+3950), and two extremely wide very-low-mass binary systems (2M0525-7425AB and 2M1348-1344AB), resulting from our search for common proper motion pairs containing ultracool components in the Two Micron All Sky Survey (2MASS) and the Wide-field Infrared Survey Explorer (WISE) catalogs. The near-infrared spectrum of 2M0614+3950 indicates a spectral type L9 \pm 1 object residing at a distance of 26.1 \pm 1.3 pc. The optical spectrum of the 2M0525-7425 primary reveals an M3.0 \pm 0.5 dwarf, accompanied by a secondary previously classified as L2. The system has an angular separation of ~44", equivalent to ~2000 AU at the 45.7 \pm 2.5 pc distance. Using optical and infrared spectra, respectively, we classify the components of 2M1348-1344AB as M4.5 \pm 0.5 and T6 \pm 1. The angular separation of ~68" is equivalent to ~1300 AU at the distance of 19.2 \pm 0.9 pc. 2M1348-1344AB is one of only five very wide (separation > 1000 AU) systems containing late T dwarfs known to date.

View original: http://arxiv.org/abs/1205.0818