Van Maanen's star (van Maanen 2) is a white dwarf star. Out of the white dwarfs known, it is the third closest to the Sun, after Sirius B and Procyon B, in that order, and the closest known solitary white dwarf.[10][11] Discovered in 1917 by Adriaan van Maanen,[12] Van Maanen's star was the third white dwarf identified, after 40 Eridani B and Sirius B, and the first that was not a member of a multi-star system.[13]

Excerpt from Wikipedia.