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Related papers: Hot white dwarfs and the UV delay in dwarf novae

200 papers

We examine the properties of white dwarfs (WDs) accreting hydrogen-rich matter in and near the stable burning regime of accretion rates as modeled by time-dependent calculations done with Modules for Experiments in Stellar Astrophysics…

Solar and Stellar Astrophysics · Physics 2015-06-17 William M. Wolf , Lars Bildsten , Jared Brooks , Bill Paxton

We present an analysis of the FUSE spectra of eight high-declination dwarf novae obtained from a Cycle 7 FUSE survey. These DN systems have not been previously studied in the UV and little is known about their white dwarfs (WDs) or…

Solar and Stellar Astrophysics · Physics 2009-08-05 P. Godon , E. M. Sion , P. E. Barrett , P. Szkody

Infrared excesses due to dusty disks have been observed orbiting white dwarfs with effective temperatures between 7200 K and 25000 K, suggesting that the rate of tidal disruption of minor bodies massive enough to create a coherent disk…

We present high resolution Hubble Space Telescope ultraviolet spectroscopy of the dwarf nova EK TrA obtained in deep quiescence. The Space Telescope Imaging Spectrograph data reveal the broad Ly-alpha absorption profile typical of a…

Astrophysics · Physics 2009-11-06 B. T. Gaensicke , P. Szkody , E. M. Sion , D. W. Hoard , S. Howell , F. H. Cheng , I. Hubeny

We have observed the short-period dwarf novae BW Scl, BC UMa and SW UMa using the Hubble Space Telescope/Space Telescope Imaging Spectrograph. In all three systems, the white dwarf is the dominant source of far-ultraviolet flux, even though…

Astrophysics · Physics 2009-11-11 B. T. Gaensicke , P. Szkody , S. B. Howell , E. M. Sion

Rapid bursts at optical wavelengths have been reported for several accreting white dwarfs, where the optical luminosity can increase by up to a factor 30 in less than an hour fading on timescales of several hours, and where the energy…

High Energy Astrophysical Phenomena · Physics 2022-04-27 S. Scaringi , P. J. Groot , C. Knigge , J. -P. Lasota , D. de Martino , Y. Cavecchi , D. A. H. Buckley , M. E. Camisassa

We present the most complete multiwavelength coverage of any dwarf nova outburst: simultaneous optical, Extreme Ultraviolet Explorer, and Rossi X-ray Timing Explorer observations of SS Cygni throughout a narrow asymmetric outburst. Our data…

Astrophysics · Physics 2009-11-10 Peter J. Wheatley , Christopher W. Mauche , Janet A. Mattei

Nova explosions are caused by global thermonuclear runaways triggered in the surface layers of accreting white dwarfs. It has been predicted that localised thermonuclear bursts on white dwarfs can also take place, similar to Type I X-ray…

We make use of the high photometric precision of Kepler to search for periodic modulations among 14 normal (DA- and DB-type, likely non-magnetic) hot white dwarfs (WDs). In five, and possibly up to seven of the WDs, we detect periodic, ~2…

Solar and Stellar Astrophysics · Physics 2015-06-22 Dan Maoz , Tsevi Mazeh , Amy McQuillan

By introducing a simplified transport model of outer layers of white dwarfs we derive an analytical semi-empirical relation which constrains effective temperature-mass-radius for white dwarfs. This relation is used to classify recent data…

Solar and Stellar Astrophysics · Physics 2017-01-10 Elvis do A. Soares

Nova explosions occur on accreting white dwarfs. A thermonuclear runaway in the H-rich accreted envelope causes its ejection without destroying the white dwarf, and an increase in the luminosity by several magnitudes. Accretion is…

High Energy Astrophysical Phenomena · Physics 2026-01-14 Gloria Sala , Frank Haberl , Axel Schwope , Dusán Tubín-Arenas , Elif Şafak , Chandreyee Maitra , Jochen Greiner

Although numerous white dwarf stars host dusty debris disks, the temperature distribution of these stars differs significantly from the white dwarf population as a whole. Dusty debris disks exist exclusively around white dwarfs cooler than…

Earth and Planetary Astrophysics · Physics 2021-06-09 Jordan K. Steckloff , John Debes , Amy Steele , Brandon Johnson , Elisabeth R. Adams , Seth A. Jacobson , Alessondra Springmann

Context. Although the disc instability model is widely accepted as the explanation for dwarf nova outbursts, it is still necessary to confront its predictions to observations because much of the constraints on angular momentum transport in…

Solar and Stellar Astrophysics · Physics 2020-04-08 J. -M. Hameury , C. Knigge , J. -P. Lasota , F. -J. Hambsch , R. James

We present the first radiation magnetohydrodynamics simulations of the atmosphere of white dwarf stars. We demonstrate that convective energy transfer is seriously impeded by magnetic fields when the plasma-beta parameter, the thermal to…

Solar and Stellar Astrophysics · Physics 2015-10-14 P. -E. Tremblay , G. Fontaine , B. Freytag , O. Steiner , H. -G. Ludwig , M. Steffen , S. Wedemeyer , P. Brassard

Gaia Data Release 2 revealed a population of ultramassive white dwarfs on the Q branch that are moving anomalously fast for a local disc population with their young photometric ages. As the velocity dispersion of stars in the local disc…

Solar and Stellar Astrophysics · Physics 2023-04-07 Leesa Fleury , Ilaria Caiazzo , Jeremy Heyl

We have carried out a combined Hubble Space Telescope (HST/GHRS) and Far Ultraviolet Spectroscopic Explorer FUSE) analysis of the prototype dwarf nova SS Cygni during quiescence. The FUSE and HST spectra were obtained at comparable times…

Solar and Stellar Astrophysics · Physics 2015-05-19 Edward Sion , Patrick Godon , Janine Myzcka , William Blair

The unprecedented extent of coverage provided by Kepler observations recently revealed outbursts in two hydrogen-atmosphere pulsating white dwarfs (DAVs) that cause hours-long increases in the overall mean flux of up to 14%. We have…

The disc instability model accounts well for most of the observed properties of dwarf novae and soft X-ray transients, but the rebrightenings, reflares, and echoes occurring at the end of outbursts or shortly after in WZ Sge stars or soft…

Solar and Stellar Astrophysics · Physics 2021-06-16 J. -M. Hameury , J. -P. Lasota

We use high-resolution time-dependent numerical simulations of accretion discs around white dwarfs to study the structure and properties of transition fronts in the context of the thermal-viscous disc instability model. The thermal…

Astrophysics · Physics 2009-10-31 Kristen Menou , Jean-Marie Hameury , Rudolf Stehle

We use the irradiated secondary star in the remnant of Nova Cyg 1975 as a probe of the cooling white dwarf. At superior conjunction the flux in the B band is dominated by the irradiated face of the secondary star. The heated face produces…

Astrophysics · Physics 2007-05-23 M. W. Somers , T. Naylor