The Distance to the Vela Supernova Remnant

Abstract

We have obtained high-resolution Ca II and Na I absorption-line spectra toward 68 OB stars in the direction of the Vela supernova remnant. The stars lie at distances of 190-2800 pc as determined by Hipparcos and spectroscopic parallax estimations. The presence of high-velocity absorption attributable to the remnant along some of the sight lines constrains the remnant distance to 250±30 pc. This distance is consistent with several recent investigations that suggest that the canonical remnant distance of 500 pc is too large.