The Solar Neighbourhood XI: The trigonometric parallax of SCR 1845--6357

Abstract

We present a trigonometric parallax for the nearby star SCR1845--6357, an extremely red high proper motion object discovered by Hambly et al. (2004) and identified via accurate photoelectric photometry and spectroscopy to be an M8.5 dwarf with a photometric parallax of $4.6\pm0.8$ pc by Henry et al. (2004). Using methods similar to those described in Deacon & Hambly (2001) we have derived a full astrometric solution from SuperCOSMOS scans of eight survey and non--survey Schmidt photographs held in the United Kingdom Schmidt Telescope Unit plate library. We calculate the trigonometric parallax to be $\pi=282\pm23$ mas yielding a distance of $3.5\pm0.3$ pc which implies an absolute K$_{s}$ magnitude of 10.79. This distance calculation places SCR1845--6357 as the 16th closest stellar system to the Sun.