A Determination of the Local Density of White Dwarf Stars

The most recent version of the Catalog of Spectroscopically Identified WhiteDwarfs lists 2249 white dwarf stars. Among these stars are 118 white dwarfsthat have either reliable trigonometric parallaxes or color-based distancemoduli which place them at a distance within 20 pc of the Sun. Most of thesenearby white dwarfs are isolated stars, but 35 (30 % of the sample) are inbinary systems, including such well known systems as Sirius A/B, and ProcyonA/B. There are also three double degenerate systems in this sample of the localwhite dwarf population. The sample of local white dwarfs is largely completeout to 13 pc and the local density of white dwarf stars is found to be (5.5 +/-0.8) x 10^-3 pc^-3 with a corresponding mass density of (3.7 +/- 0.5) x10^-3 Mpc^-3.Comment: 20 pages, 3 Postscript figure