Detections and constraints on white dwarf variability from time-series GALEX observations
Tucker, Michael A.
Shappee, Benjamin J.
Hermes, James J.
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Citation (published version)D.M. Rowan, Michael A. Tucker, Benjamin J. Shappee, James J. Hermes. 2019. "Detections and constraints on white dwarf variability from time-series GALEX observations." Monthly Notices of the Royal Astronomical Society, Volume 486, Issue 4, pp. 4574 - 4589. https://doi.org/10.1093/mnras/stz1116
We search for photometric variability in more than 23 000 known and candidate white dwarfs (WDs), the largest ultraviolet survey compiled for a single study of WDs. We use GPHOTON, a publicly available calibration/reduction pipeline, to generate time-series photometry of WDs observed by GALEX. By implementing a system of weighted metrics, we select sources with variability due to pulsations and eclipses. Although GALEX observations have short baselines (≤30 min), we identify intrinsic variability in sources as faint as Gaia G = 20 mag. With our ranking algorithm, we identify 48 new variable WDs in archival GALEX observations. We detect 40 new pulsators: 36 have hydrogen-dominated atmospheres (DAVs), including one possible massive DAV, and four are helium-dominated pulsators (DBVs). We also detect eight new eclipsing systems; five are new discoveries, and three were previously known spectroscopic binaries. We perform synthetic injections of the light curve of WD 1145+017, a system with known transiting debris, to test our ability to recover similar systems. We find that the 3σ maximum occurrence rate of WD 1145+017-like transiting objects is ≤0.5 per cent.
RightsThis article has been accepted for publication in Monthly Notices of the Royal Astronomical Society, Volume 486, Issue 4, pp. 4574 - 4589. © 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.