Stein 2051
Stein 2051 is a nearby binary star system, containing a red dwarf and a degenerate star , located in constellation Camelopardalis at about 18 ly from Earth.
Stein 2051 is the nearest separate binary 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.Properties
The brighter of this two stars is A, but the more massive is component B.
In 2017, Stein 2051 B was observed passing in front of a more distant star. 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, which fits the expected range of a white dwarf with a carbon-oxygen core.
