Discovery of a ZZ Ceti in the Kepler Mission Field

TL;DR

This paper reports the discovery of the first pulsating DA white dwarf in the Kepler field, identified through ground-based observations and confirmed with spectroscopy, with potential for detailed asteroseismic study using Kepler data.

Contribution

It is the first identification of a ZZ Ceti star in the Kepler field, enabling unprecedented asteroseismic analysis of white dwarf interiors.

Findings

Discovered a ZZ Ceti star in the Kepler field.

Confirmed the star's temperature and gravity placing it within the instability strip.

Observed variability with periods between 800 and 1450 seconds.

Abstract

We report the discovery of the first identified pulsating DA white dwarf in the field of the Kepler mission, WD J1916+3938 (Kepler ID 4552982). This ZZ Ceti star was first identified through ground-based, time-series photometry, and follow-up spectroscopy confirm it is a hydrogen-atmosphere white dwarf with an effective temperature = 11,129 $\pm$ 115 K and log g = 8.34 $\pm$ 0.06, placing it within the empirical ZZ Ceti instability strip. The object shows up to 0.5 percent amplitude variability at several periods between 800 -- 1450 s. Extended Kepler observations of this object could yield the best lightcurve, to-date, of any pulsating white dwarf, allowing us to directly study the interior of an evolved object representative of the fate of the majority of stars in our Galaxy.