The Gaia 20 pc white dwarf sample

TL;DR

This paper compiles an updated, highly complete sample of white dwarfs within 20 parsecs using Gaia DR2 data, identifying new systems, analyzing their properties, and estimating the local white dwarf space density.

Contribution

It provides the most current and complete catalog of nearby white dwarfs from Gaia DR2, including new detections and binary system analysis.

Findings

Identified 139 white dwarf systems within 20 pc, including 9 new detections.

Estimated the local white dwarf space density as (4.49±0.38)×10⁻³ pc⁻³.

Re-identified all known binaries with Gaia DR2 data, confirming binarity of one new white dwarf.

Abstract

Using Gaia DR2 data, we present an up-to-date sample of white dwarfs within 20 pc of the Sun. In total we identified 139 systems in Gaia DR2, nine of which are new detections, with the closest of these located at a distance of 13.05 pc. We estimated atmospheric parameters for all stellar remnants based on the Gaia parallaxes and photometry. The high precision and completeness of the Gaia astrometry allowed us to search for wide binary companions. We re-identified all known binaries where both components have accurate DR2 astrometry, and established the binarity of one of the nine newly identified white dwarfs. No new companions were found to previously known 20 pc white dwarfs. Finally, we estimated the local white dwarf space-density to be $(4.49\pm0.38)\times10^{-3}$ pc$^{-3}$, having given careful consideration to the distance-dependent Gaia completeness, which misses known objects at short distances, but is close to complete for white dwarfs near 20 pc.