Multi-band photometry and spectroscopy of an all-sky sample of bright white dwarfs

TL;DR

This paper compiles a comprehensive all-sky catalogue of bright white dwarfs with photometry and spectroscopy, aiding TESS in identifying and characterizing white dwarf targets for asteroseismology and planetary debris searches.

Contribution

It provides the first extensive all-sky photometric and spectroscopic dataset of bright white dwarfs, including new confirmations and candidate identifications, supporting TESS and Gaia missions.

Findings

Confirmed 82 white dwarfs and 25 hot subdwarfs through spectroscopy.

Discovered six pulsating white dwarf candidates and nine white dwarf binaries.

Identified a nearby white dwarf at 25 pc from the Sun.

Abstract

The upcoming NASA Transiting Exoplanet Survey Satellite (TESS) will obtain space-based uninterrupted light curves for a large sample of bright white dwarfs distributed across the entire sky, providing a very rich resource for asteroseismological studies and the search for transits from planetary debris. We have compiled an all-sky catalogue of ultraviolet, optical, and infrared photometry as well as proper motions, which we propose as an essential tool for the preliminary identification and characterisation of potential targets. We present data for 1864 known white dwarfs and 305 high-probability white dwarf candidates brighter than 17 mag. We describe the spectroscopic follow-up of 135 stars, of which 82 are white dwarfs and 25 are hot subdwarfs. The new confirmed stars include six pulsating white dwarf candidates (ZZ Cetis), and nine white dwarf binaries with a cool main-sequence companion. We identify one star with a spectroscopic distance of only 25 pc from the Sun. Around the time TESS is launched, we foresee that all white dwarfs in this sample will have trigonometric parallaxes measured by the ESA Gaia mission next year.