The Pulsating Helium-Atmosphere White Dwarfs I: New DBVs from the Sloan Digital Sky Survey

Abstract

We present a dedicated search for new pulsating helium-atmosphere (DBV) white dwarfs from the Sloan Digital Sky Survey using the McDonald 2.1m Otto Struve Telescope. In total we observed 55 DB and DBA white dwarfs with spectroscopic temperatures between 19,000 and 35,000K. We find 19 new DBVs and place upper limits on variability for the remaining 36 objects. In combination with previously known DBVs, we use these objects to provide an update to the empirical extent of the DB instability strip. With our sample of new DBVs, the red edge is better constrained, as we nearly double the number of DBVs known between 20,000 and 24,000K. We do not find any new DBVs hotter than PG 0112+104, the current hottest DBV at $T_{\mathrm{eff}}\approx$ 31,000K, but do find pulsations in four DBVs with temperatures between 27,000 and 30,000K, improving empirical constraints on the poorly defined blue edge. We investigate the ensemble pulsation properties of all currently known DBVs, finding that the weighted mean period and total pulsation power exhibit trends with effective temperature that are qualitatively similar to the pulsating hydrogen-atmosphere white dwarfs.

19 pages, 8 figures, 5 tables. Accepted to ApJ

References in corpus (30)

• Estimating distances from parallaxes. V: Geometric and photogeometric distances to 1.47 billion stars in Gaia Early Data Release 3
• The Chemical Composition of an Extrasolar Minor Planet
• A catalogue of white dwarfs in Gaia EDR3
• On the Spectral Evolution of Hot White Dwarf Stars. I. A Detailed Model-Atmosphere Analysis of Hot White Dwarfs from SDSS DR12
• New white dwarf stars in the Sloan Digital Sky Survey Data Release 10
• White Dwarf Rotation as a Function of Mass and a Dichotomy of Mode Linewidths: Kepler Observations of 27 Pulsating DA White Dwarfs Through K2 Campaign 8
• On the Measurement of Fundamental Parameters of White Dwarfs in the Gaia Era
• White dwarf and subdwarf stars in the Sloan Digital Sky Survey Data Release 14
• I Spy Transits and Pulsations: Empirical Variability in White Dwarfs Using Gaia and the Zwicky Transient Facility
• Hot DB White Dwarfs from the Sloan Digital Sky Survey
• Compositions of Planetary Debris around Dusty White Dwarfs
• Polluted White Dwarfs: Mixing Regions and Diffusion Timescales
• Solar Abundances of Rock Forming Elements, Extreme Oxygen and Hydrogen in a Young Polluted White Dwarf
• White dwarf pollution by hydrated planetary remnants: Hydrogen and Metals in WD J204713.76-125908.9
• Pruning The ELM Survey: Characterizing Candidate Low-Mass White Dwarfs Through Photometric Variability
• A deep test of radial differential rotation in a helium-atmosphere white dwarf: I. Discovery of pulsations in PG 0112+104
• 3D spectroscopic analysis of helium-line white dwarfs
• TESS first look at evolved compact pulsators: asteroseismology of the pulsating helium-atmosphere white dwarf TIC 257459955
• New developments of the ZZ Ceti instability strip: The discovery of eleven new variables
• Searching for ZZ Ceti White Dwarfs in the Gaia Survey
• Detections and Constraints on White Dwarf Variability from Time-Series GALEX Observations
• New Pulsating DB White Dwarf Stars from the Sloan Digital Sky Survey
• Periodic Variations in the O-C Diagrams of Five Pulsation Frequencies of the DB White Dwarf EC 20058-5234
• Whole Earth Telescope observations of the hot helium atmosphere pulsating white dwarf EC 20058-5234
• Destroying Aliases from the Ground and Space: Super-Nyquist ZZ Cetis in K2 Long Cadence Data
• Revealing the pulsational properties of the V777 Her star KUV 05134+2605 by its long-term monitoring
• Limits on Mode Coherence in Pulsating DA White Dwarfs Due to a Non-static Convection Zone
• Atmospheric parameters and carbon abundance for hot DB white dwarfs
• The pulsating white dwarf G117-B15A: still the most stable optical clock known
• EPIC 228782059: Asteroseismology of what could be the coolest pulsating helium-atmosphere white dwarf (DBV) known?

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