Measuring White Dwarf Variability from Sparsely Sampled Gaia DR3 Multi-Epoch Photometry
Abstract
White dwarf stars are ubiquitous in the Galaxy, and are essential to understanding stellar evolution. While most white dwarfs are photometrically stable and reliable flux standards, some can be highly variable, which can reveal unique details about the endpoints of low-mass stellar evolution. In this study we characterize a sample of high-confidence white dwarfs with multi-epoch photometry from Gaia Data Release 3. We compare these Gaia light curves with light curves from the Zwicky Transiting Facility and the Transiting Exoplanet Survey Satellite to see when Gaia data independently can accurately measure periods of variability. From this sample, 105 objects have variability periods measured from the Gaia light curves independently, with periods as long as roughly 9.5 d and as short as 256.2 s (roughly 4 min), including seven systems with periods shorter than 1000 s. We discover 86 new objects from the 105 target sample, including pulsating, spotted, and binary white dwarfs, and even a new 68.4 min eclipsing cataclysmic variable. The median amplitude of the absolute photometric variability we confirm from Gaia independently is 1.4%, demonstrating that Gaia epoch photometry is capable of measuring short-term periods even when observations are sparse.
Cite
@article{arxiv.2404.02201,
title = {Measuring White Dwarf Variability from Sparsely Sampled Gaia DR3 Multi-Epoch Photometry},
author = {Maya Steen and J. J. Hermes and Joseph A. Guidry and Annabelle Paiva and Jay Farihi and Tyler M. Heintz and Brison B. Ewing and Nathanial Berry},
journal= {arXiv preprint arXiv:2404.02201},
year = {2024}
}
Comments
22 pages, 8 figures, 3 tables, accepted for publication in ApJ; updated headers in table 3 to reflect correct units of amplitude; updated formatting for readability