Stein 2051

Stein 2051 (Gliese 169.1, G 175-034, LHS 26/27) is a nearby binary star system, containing a red dwarf (component A) and a degenerate star (white dwarf) (component B), located in constellation Camelopardalis at about 18 ly from Earth.

[12] Stein 2051 is the nearest (red dwarf + white dwarf) separate binary system (40 Eridani BC is located closer at 16.26 light-years,[13] but it is a part of a triple star system).

Stein 2051 B is the 6th nearest white dwarf after Sirius B, Procyon B, van Maanen's star, LP 145-141 and 40 Eridani B.

The bending of starlight by the gravitational field of the nearer star allowed its mass to be directly measured.

The estimated mass of Stein 2051 B is 0.675±0.051 M☉, which fits the expected range of a white dwarf with a carbon-oxygen core.