* Astronomy

Title: The nearby young visual binary HIP 115147 and its common proper motion companion LSPM J2322+7847
Authors: V. V. Makarov, N. Zacharias, G. S. Hennessy, H. C. Harris, A. K. B. Monet

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{\'e}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 51.6 ±0.8 mas, in good agreement with the Hipparcos parallax of the primary star (50.7 ±0.6 mas). Our BVRI photometric data and near-infrared data from 2MASS are consistent with LSPM J2322+7847 being brighter by 1 magnitude in K_s than field M dwarfs at V-K_s=6.66, 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 analogue PZ Tel (age 12-20 Myr) and members of the TWA association (7 Myr).

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