Published online by Cambridge University Press: 14 August 2015
Van Maanen's star (1950: 0h46.m5, + 5°.09′) is a white dwarf (visual magnitude 12.4, spectrum DF) with a proper motion of 2″.95 in 155°.5 and parallax 0″.234. An early determination of radial velocity yielded +238 km/sec (Adams and Joy, 1926). It was suggested by Russell and Atkinson (1931) that van Maanen's star might show a very large Einstein shift of at least +700 km/sec. Oort (1932) pointed out that the observed value of +238 km/sec is incompatible with the theory of galactic rotation: this would support the Einstein shift interpretation.