Published online by Cambridge University Press: 12 April 2016
Photographic observations of the large proper motion binary, Stein 2051, extended over the period 1966–87, do not support that it is a triple system as previously reported (Strand, 1977). The orbital motion is nearly linear over this interval? however, when results of plates from the Vatican Astrographic Zone from 1908–11 are included, a mass ratio is obtained, leading to a mass of 0.50©for the white dwarf component, given the calculated mass of 0.24© for the red dwarf component.