A Census of White Dwarfs Within 40 Parsecs of the Sun

TL;DR

This paper aims to create a comprehensive catalog of white dwarfs within 40 parsecs of the Sun by utilizing proper motion data and spectroscopic analysis, significantly improving the current census.

Contribution

It introduces a new method combining proper motion data with spectroscopic follow-up to identify and characterize nearby white dwarfs, expanding the known population.

Findings

Preliminary sample of spectroscopically confirmed white dwarfs.

Atmospheric parameters obtained for various white dwarf types.

Identification of candidates within 50 parsecs for further study.

Abstract

Our aim is to compile a catalog of white dwarfs within 40 parsecs of the Sun, in which newly discovered objects would significantly increase the completeness of the current census. White dwarf candidates are identified from the SUPERBLINK proper motion database (Lepine & Shara 2005), which allows us to investigate stars down to a proper motion limit as low as 40 mas yr-1. The selection criteria and distance estimates are based on a combination of color-magnitude and reduced proper motion diagrams. Candidates with distances less than 50 parsecs are selected for spectroscopic follow-up. We present our preliminary sample of spectroscopically confirmed white dwarfs, as well as their atmospheric parameters. These parameters are obtained using the spectroscopic technique developed in Bergeron et al.(1992) for DA stars. DB, DQ, and DZ stars are also analyzed spectroscopically. For featureless spectra as well as those showing only Halpha, we perform a detailed photometric analysis of their energy distribution.