The Parallax of VHS J1256-1257 from CFHT and Pan-STARRS 1

Abstract

We present new parallax measurements from the CFHT Infrared Parallax Program and the Pan-STARRS 3$\ddot{I}€$ Steradian Survey for the young ($\approx 150-300$ Myr) triple system VHS J125601.92$-$125723.9. This system is composed of a nearly equal-flux binary ("AB") and a wide, possibly planetary-mass companion ("b"). The system's published parallactic distance ($12.7\pm 1.0$ pc) implies absolute magnitudes unusually faint compared to known young objects and is in tension with the spectrophotometric distance for the central binary ($17.2\pm 2.6$ pc). Our CFHT and Pan-STARRS parallaxes are consistent, and the more precise CFHT result places VHS J1256-1257 at $22.2_{-1.2}^{+1.1}$ pc. Our new distance results in higher values for the companion's mass ($19\pm 5$ M${}_{\mathrm{Jup}}$) and temperature ($1240\pm 50$ K), and also brings the absolute magnitudes of all three components into better agreement with known young objects.

Research Notes of the American Astronomical Society, in press. Arxiv version has additional information about the astrometry (text & figure)