591 citations · 2.5k across the 35 of their papers we have counts for
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Kepler and TESS Observations of PG 1159-035
Gabriela Oliveira da Rosa, S. O. Kepler, Alejandro H. Córsico +11
PG 1159-035 is the prototype of the DOV hot pre-white dwarf pulsators. It was observed during the Kepler satellite K2 mission for 69 days in 59 s cadence mode and by the TESS satel…
I Spy Transits and Pulsations: Empirical Variability in White Dwarfs Using Gaia and the Zwicky Transient Facility
Joseph A. Guidry, Zachary P. Vanderbosch, J. J. Hermes +13
We present a novel method to detect variable astrophysical objects and transient phenomena using anomalous excess scatter in repeated measurements from public catalogs of Gaia DR2…
An Isolated White Dwarf with 317-Second Rotation and Magnetic Emission
Joshua S. Reding, J. J. Hermes, Z. Vanderbosch +5
We report the discovery of short-period photometric variability and modulated Zeeman-split hydrogen emission in SDSSJ125230.93-023417.72 (EPIC 228939929), a variable white dwarf st…
Limits on Mode Coherence in Pulsating DA White Dwarfs Due to a Non-static Convection Zone
M. H. Montgomery, J. J. Hermes, D. E. Winget +2
The standard theory of pulsations deals with the frequencies and growth rates of infinitesimal perturbations in a stellar model. Modes which are calculated to be linearly driven sh…
A White Dwarf with Transiting Circumstellar Material Far Outside the Roche Limit
Z. Vanderbosch, J. J. Hermes, E. Dennihy +9
We report the discovery of a white dwarf exhibiting deep, irregularly shaped transits, indicative of circumstellar planetary debris. Using Zwicky Transient Facility DR2 photometry…
Core crystallization and pile-up in the cooling sequence of evolving white dwarfs
Pier-Emmanuel Tremblay, Gilles Fontaine, Nicola Pietro Gentile Fusillo +7
White dwarfs are stellar embers depleted of nuclear energy sources that cool over billions of years. These stars, which are supported by electron degeneracy pressure, reach densiti…
Analysis of Helium-Rich White Dwarfs Polluted by Heavy Elements in the Gaia Era
S. Coutu, P. Dufour, P. Bergeron +4
We present a homogeneous analysis of 1023 DBZ/DZ(A) and 319 DQ white dwarf stars taken from the Montreal White Dwarf Database. This represents a significant increase over the previ…
Dusty Exoplanetary Debris Disks in the Single-Temperature Blackbody Plane
E. Dennihy, J. C. Clemens, B. H. Dunlap
We present a bulk sample analysis of the metal polluted white dwarfs which also host infrared bright dusty debris disks, known to be direct signatures of an active exoplanetary acc…
Rapid Evolution of the Gaseous Exoplanetary Debris Around the White Dwarf Star HE 1349--2305
E. Dennihy, J. C. Clemens, B. H. Dunlap +3
Observations of heavy metal pollution in white dwarf stars indicate that metal-rich planetesimals are frequently scattered into star-grazing orbits, tidally disrupted, and accreted…
WIRED for EC: New White Dwarfs with Infrared Excesses and New Classification Schemes from the Edinburgh-Cape Blue Object Survey
E. Dennihy, J. C. Clemens, John H. Debes +4
We present a simple method for identifying candidate white dwarf systems with dusty exoplanetary debris based on a single temperature blackbody model fit to the infrared excess. We…
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
J. J. Hermes, B. T. Gaensicke, Steven D. Kawaler +15
We present photometry and spectroscopy for 27 pulsating hydrogen-atmosphere white dwarfs (DAVs, a.k.a. ZZ Ceti stars) observed by the Kepler space telescope up to K2 Campaign 8, an…
The Solar Neighborhood. XXXIX. Parallax Results from the CTIOPI and NOFS Programs: 50 New Members of the 25 Parsec White Dwarf Sample
John P. Subasavage, Wei-Chun Jao, Todd J. Henry +9
We present 114 trigonometric parallaxes for 107 nearby white dwarf (WD) systems from both the Cerro Tololo Inter-American Observatory Parallax Investigation (CTIOPI) and the U. S.…
Evidence from K2 for rapid rotation in the descendant of an intermediate-mass star
J. J. Hermes, Steven D. Kawaler, A. D. Romero +9
Using patterns in the oscillation frequencies of a white dwarf observed by K2, we have measured the fastest rotation rate, 1.13(02) hr, of any isolated pulsating white dwarf known…
A deep test of radial differential rotation in a helium-atmosphere white dwarf: I. Discovery of pulsations in PG 0112+104
J. J. Hermes, Steven D. Kawaler, A. Bischoff-Kim +3
We present the detection of non-radial oscillations in a hot, helium-atmosphere white dwarf using 78.7 d of nearly uninterrupted photometry from the Kepler space telescope. With an…
Seismology of an Ensemble of ZZ Ceti Stars
J. C. Clemens, P. C. O'Brien, Bart H. Dunlap +1
We combine all the reliably-measured eigenperiods for hot, short-period ZZ Ceti stars onto one diagram and show that it has the features expected from evolutionary and pulsation th…
Understanding Systematics in ZZ Ceti Model Fitting to Enable Differential Seismology
J. T. Fuchs, Bart H. Dunlap, J. C. Clemens +3
We are conducting a large spectroscopic survey of over 130 Southern ZZ Cetis with the Goodman Spectrograph on the SOAR Telescope. Because it employs a single instrument with high U…
A subtle IR excess associated with a young White Dwarf in the Edinburgh-Cape Blue Object Survey
E. Dennihy, John H. Debes, B. H. Dunlap +3
We report the discovery of a subtle infrared excess associated with the young white dwarf EC\,05365--4749 at 3.35 and 4.6\,m. Follow-up spectroscopic observations are consistent…
The Magnetic Cataclysmic Variable LSQ1725-64
J. T. Fuchs, Bart H. Dunlap, E. Dennihy +7
We present new photometry and spectroscopy of the 94m eclipsing binary LSQ1725-64 that provide insight into the fundamental parameters and evolutionary state of this system. We con…
A second case of outbursts in a pulsating white dwarf observed by Kepler
J. J. Hermes, M. H. Montgomery, Keaton J. Bell +7
We present observations of a new phenomenon in pulsating white dwarf stars: large-amplitude outbursts at timescales much longer than the pulsation periods. The cool (Teff = 11,010…
Insights into internal effects of common-envelope evolution using the extended Kepler mission
J. J. Hermes, B. T. Gaensicke, A. Bischoff-Kim +14
We present an analysis of the binary and physical parameters of a unique pulsating white dwarf with a main-sequence companion, SDSS J1136+0409, observed for more than 77 d during t…
An eclipsing post common-envelope system consisting of a pulsating hot subdwarf B star and a brown dwarf companion
V. Schaffenroth, B. N. Barlow, H. Drechsel +1
Hot subdwarf B stars (sdBs) are evolved, core helium-burning objects located on the extreme horizontal branch. Their formation history is still puzzling as the sdB progenitors must…
A 1.05 Companion to PSR J2222-0137: The Coolest Known White Dwarf?
David L. Kaplan, Jason Boyles, Bart H. Dunlap +5
The recycled pulsar PSR J2222-0137 is one of the closest known neutron stars, with a parallax distance of pc and an edge-on orbit. We measure the Shapiro delay…
A progenitor binary and an ejected mass donor remnant of faint type Ia supernovae
S. Geier, T. R. Marsh, B. Wang +17
Type Ia supernovae (SN Ia) are the most important standard candles for measuring the expansion history of the universe. The thermonuclear explosion of a white dwarf can explain the…
EC 10246-2707: a new eclipsing sdB + M dwarf binary
B. N. Barlow, D. Kilkenny, H. Drechsel +10
We announce the discovery of a new eclipsing hot subdwarf B + M dwarf binary, EC 10246-2707, and present multi-colour photometric and spectroscopic observations of this system. Sim…