The nearby young visual binary HIP 115147 and its common proper motion companion LSPM J2322+7847
arXiv:0709.0949 · doi:10.1086/522887
Abstract
We report a late M-type, common proper motion companion to a nearby young visual binary HIP 115147 (V368 Cep), separated by 963 arcseconds from the primary K0 dwarf. This optically dim star has been identified as a candidate high proper motion, nearby dwarf LSPM J2322+7847 by L{é}pine in 2005. The wide companion is one of the latest post-T Tauri low mass stars found within 20 pc. We obtain a trigonometric parallax of mas, in good agreement with the Hipparcos parallax of the primary star ( mas). Our photometric data and near-infrared data from 2MASS are consistent with LSPM J2322+7847 being brighter by 1 magnitude in than field M dwarfs at , which indicates its pre-main sequence status. We conclude that the most likely age of the primary HIP 115147 and its 11-arcsecond companion HIP 115147B is 20-50 Myr. The primary appears to be older than its close analog PZ Tel (age 12-20 Myr) and members of the TWA association (7 Myr).
accepted in ApJL