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Related papers: New Pulsating White Dwarfs in Cataclysmic Variable…

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We present some of the results of a survey aimed at exploring the asteroseismological potential of the newly-discovered carbon-atmosphere white dwarfs. We show that, in certains regions of parameter space, carbon-atmosphere white dwarfs may…

Solar and Stellar Astrophysics · Physics 2009-07-22 G. Fontaine , P. Brassard , P. Dufour , E. M. Green , J. Liebert

We report the discovery of four massive ($M > 0.8\,M_\odot$) ZZ Ceti white dwarfs, including an ultramassive $1.16\,M_\odot$ star. We obtained ground based, time-series photometry for thirteen white dwarfs from the Sloan Digital Sky Survey…

Solar and Stellar Astrophysics · Physics 2017-04-12 Brandon Curd , A. Gianninas , Keaton J. Bell , Mukremin Kilic , A. D. Romero , Carlos Allende Prieto , D. E. Winget , K. I. Winget

We discuss the properties of 137 cataclysmic variables (CVs) which are included in the Sloan Digital Sky Survey (SDSS) spectroscopic data base, and for which accurate orbital periods have been measured. 92 of these systems are new…

We report on the spectroscopic confirmation of 68 new bright ($G=13.5-17.2$ mag) and blue (pre-)white dwarfs (WDs). This finding has allowed us to almost double the number of the hottest ($T_{\mathrm{eff}} \geq 60$kK) known WDs brighter…

We present time-series photometry of 31 massive DA white dwarfs with $M\gtrsim 0.9~M_\odot$ within the ZZ Ceti instability strip from the Montreal White Dwarf Database 100 pc sample. The majority of the targets had no previous time-series…

The dwarf nova GW Librae is the first cataclysmic variable discovered to have a primary in a white dwarf instability strip, making it the first multi-mode, nonradially-pulsating star known to be accreting. The primaries of CVs, embedded in…

This paper continues the series that identifies new cataclysmic variables found in the Sloan Digital Sky Survey. We present 36 cataclysmic variables and one possible symbiotic star from Sloan spectra obtained during 2002, of which 34 are…

We present time resolved CCD photometry of 15 cataclysmic variables (CVs) identified by the Sloan Digital Sky Survey (SDSS). The data were obtained as part of the 2004/05 International Time Programme on La Palma. We discuss the morphology…

Multi-band photometric surveys provide a straightforward way to discover and classify astrophysical objects systematically, enabling the study of a large number of targets at relatively low cost. Here we introduce an alternative approach to…

We report the discovery of the first pulsating extremely low mass (ELM) white dwarf (WD), SDSS J184037.78+642312.3 (hereafter J1840). This DA (hydrogen-atmosphere) WD is by far the coolest and the lowest-mass pulsating WD, with Teff = 9100…

Solar and Stellar Astrophysics · Physics 2015-06-04 J. J. Hermes , M. H. Montgomery , D. E. Winget , Warren R. Brown , Mukremin Kilic , Scott J. Kenyon

Our recent theoretical work (Townsley and Bildsten 2002) on the thermal state of white dwarfs (WDs) in low mass transfer rate binaries allows us to predict the broadband colors of the binary from those of the WD and companion when the disk…

Astrophysics · Physics 2007-05-23 Dean M. Townsley , Lars Bildsten

Accreting white dwarfs in Cataclysmic variables (CVs) show short-period (tens of minutes) brightness variations that are consistent with non-radial oscillations similar to gravity (g) modes observed in isolated white dwarfs (WDs). GW…

Solar and Stellar Astrophysics · Physics 2023-07-19 Praphull Kumar , Dean M. Townsley

Taking advantage of the now available Gaia EDR3 parallaxes, we carry out an archival {\it Hubble Space Telescope} (HST) far ultraviolet spectroscopic analysis of 10 cataclysmic variable systems, including 5 carefully selected eclipsing…

Solar and Stellar Astrophysics · Physics 2022-03-30 Patrick Godon , Edward M. Sion

Hot white dwarfs with carbon-dominated atmospheres (hot DQs) are a cryptic class of white dwarfs. In addition to their deficiency of hydrogen and helium, most of these stars are highly magnetic, and a large fraction vary in luminosity. This…

Solar and Stellar Astrophysics · Physics 2016-01-21 Kurtis A. Williams , M. H. Montgomery , D. E. Winget , Ross E. Falcon , Michael Bierwagon

Identification of white dwarfs (WD) with main-sequence (MS) companions and characterization of their properties can put important constraints on our understanding of binary stellar evolution and guide the theoretical predictions for a wide…

Solar and Stellar Astrophysics · Physics 2023-11-27 Prasanta K. Nayak , Anindya Ganguly , Sourav Chatterjee

We present VLT and Magellan spectroscopy and NTT photometry of nine faint cataclysmic variables (CVs) which were spectroscopically identified by the SDSS. We measure orbital periods for five of these from the velocity variations of the…

We present the results of a search for pulsations in six of the recently discovered carbon-atmosphere white dwarf ("hot DQ") stars. Based on our theoretical calculations, the star SDSS J142625.71+575218.3 is the only object expected to…

Non-radial pulsations have been identified in a number of accreting white dwarfs in cataclysmic variables. These stars offer insight into the excitation of pulsation modes in atmospheres with mixed compositions of hydrogen, helium, and…

We identify seven new ultracool white dwarfs discovered in the Sloan Digital Sky Survey (SDSS). The SDSS photometry, spectra, and proper motions are presented, and additional BVRI data are given for these and other previously discovered…

The ESA gamma-ray telescope, INTEGRAL, is detecting relatively more intrinsically rare cataclysmic variables (CVs) than were found by surveys at lower energies. Specifically, a large fraction of the CVs that are INTEGRAL sources consists of…

Solar and Stellar Astrophysics · Physics 2009-11-13 Magaretha L. Pretorius