Van Biesbroeck 3 - A low-luminosity white dwarf, not an M dwarf

W. E. Kunkel, J. Liebert, T. A. Boroson
1984 Publications of the Astronomical Society of the Pacific  
Photometry and spectrophotometry of VB3, the distant companion to HR 3018, show it to be a white dwarf of low luminosity (M ~ +15.6) and not an M dwarf. The pair provides the best available example of a very old white dwarf with a main-sequence star of sufficiently early type that a useful empirical limit may eventually be derivable for the ages of the oldest degenerate stars.
doi:10.1086/131450 fatcat:dj2rkqoncrfgxmtjn6cmwpgsxy