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Related papers: Eclipse mapping the flickering sources in the dwar…

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The physical mechanisms driving angular momentum transport in accretion discs are still unknown. Although it is generally accepted that, in hot discs, the turbulence triggered by the magneto-rotational instability is at the origin of the…

Solar and Stellar Astrophysics · Physics 2012-09-19 Iwona Kotko , Jean-Pierre Lasota

We present results from a study of TESS observations of the eclipsing dwarf nova system Z Cha, covering both an outburst and a superoutburst. We discover that Z Cha undergoes hysteretic loops in eclipse depth - out-of-eclipse flux space in…

High Energy Astrophysical Phenomena · Physics 2019-08-07 J. M. C. Court , S. Scaringi , S. Rappaport , Z. Zhan , C. Littlefield , N. Castro Segura , C. Knigge , T. Maccarone , M. Kennedy , P. Szkody , P. Garnavich

The recurrent nova T Pyxidis has erupted six times since 1890, with its last outburst in 2011, and the relatively short recurrence time between classical nova explosions indicates that T Pyx must have a massive white dwarf accreting at a…

Solar and Stellar Astrophysics · Physics 2024-09-04 P. Godon , E. M. Sion , R. E. Williams , M. J. Darnley , J. L. Sokoloski , S. S. lawrence

We have analysed a series of Suzaku data and one dataset of XMM-Newton of the SU UMa type dwarf nova VW Hyi in optical quiescence. The observed spectra in the 0.2-10 keV band are moderately well represented by multi-temperature thermal…

High Energy Astrophysical Phenomena · Physics 2019-07-31 Nozomi Nakaniwa , Takayuki Hayashi , Mai Takeo , Manabu Ishida

T~Coronae Borealis is the nearest symbiotic recurrent nova. Twice in the last two centuries, in 1866 and 1946, the accreted material ignited on the surface of the white dwarf via runaway thermonuclear fusion reactions and produced a nova…

Solar and Stellar Astrophysics · Physics 2025-08-06 Wagner Schlindwein , Raymundo Baptista , Gerardo Juan Manuel Luna

We present ground-based optical and near infrared photometric observations and Hubble Space Telescope COS spectroscopic observations of the old nova V842 Cen (Nova Cen 1986). Analysis of the optical light curves reveals a peak at 56.5 +/-…

Solar and Stellar Astrophysics · Physics 2015-06-16 Edward M. Sion , Paula Szkody , Anjum Mukadam , Brian Warner , Patrick Woudt , Frederic Walter , Arne Henden , Patrick Godon

Context. The disc instability model (DIM) successfully explains why many accreting compact binary systems exhibit outbursts, during which their luminosity increases by orders of magnitude. The DIM correctly predicts which systems should be…

High Energy Astrophysical Phenomena · Physics 2017-04-12 J. -M. Hameury , J. -P. Lasota , C. Knigge , E. G. Körding

Using the disc instability model and a simple but physically reasonable model for the X-ray, extreme UV, UV and optical emission of dwarf novae we investigate the time lags observed between the rise to outburst at different wavelengths. We…

Astrophysics · Physics 2009-11-10 Matthias R. Schreiber , Jean-Marie Hameury , Jean-Pierre Lasota

We performed time-resolved spectroscopic studies of the double-eclipsing dwarf nova EX Dra (formerly HS 1804 + 6753) in order to locate line emitting sites in the system. Optical spectra recorded during the quiescent as well as during the…

Astrophysics · Physics 2007-05-23 Viki Joergens , Karl-Heinz Mantel , Heinz Barwig , Otto Baernbantner , Hauke Fiedler

We propose a simple explanation for the constant mean brightness observed between outbursts in dwarf novae. Secular changes in the total energy dissipation rate of the accretion disc brought about by variations in surface density,…

Astrophysics · Physics 2009-11-10 M. R. Truss , G. A. Wynn , P. J. Wheatley

We present Hubble Space Telescope ultraviolet spectroscopy of the recurrent nova T Pyxidis obtained more than 5 years after its 2011 outburst indicating that the system might not have yet reached its deep quiescent state. The ultraviolet…

Solar and Stellar Astrophysics · Physics 2018-08-08 Patrick Godon , Edward Sion , Robert Williams , Sumner Starrfield

An optical light curve of SU UMa type dwarf nova V1504 Cyg taken by Kepler was analysed in order to study fast optical variability (flickering). We calculated power density spectra and rms-flux relations for two different stages of…

Solar and Stellar Astrophysics · Physics 2015-05-21 A. Dobrotka , J. -U. Ness

We obtained time-resolved optical photometry and spectroscopy of the nova-like variable KR Aurigae in the low state. The spectrum reveals a DAB white dwarf and a mid-M dwarf companion. Using the companion star's $i$-band ellipsoidal…

We report on the R-band eclipse mapping analysis of high-speed photometry of the dwarf nova EX Dra on the rise to the maximum of the November 1995 outburst. The eclipse map shows a one-armed spiral structure of ~180 degrees in azimuth,…

Astrophysics · Physics 2009-10-31 Raymundo Baptista , M. S. Catalan

The disk instability model attributes the outbursts of dwarf novae to a thermal-viscous instability of their accretion disk, an instability to which nova-like stars are not subject. We aim to test the fundamental prediction of the disk…

High Energy Astrophysical Phenomena · Physics 2018-09-19 Guillaume Dubus , Magdalena Otulakowska-Hypka , Jean-Pierre Lasota

The evidence presented earlier by several authors for the substantial disk eccentricity in dwarf novae during their superoutbursts is shown to result either from errors or from arbitrary, incorrect assumptions. In particular, the evidence…

Solar and Stellar Astrophysics · Physics 2009-04-15 J. Smak

We present an analysis of CCD photometric observations of the eclipsing novalike cataclysmic variable DW UMa obtained in two different luminosity states: high and intermediate. The star presents eclipses with very different depth: ~1.2 mag…

Astrophysics · Physics 2009-11-10 V. Stanishev , Z. Kraicheva , H. M. J. Boffin , V. Genkov , C. Papadaki , S. Carpano

Recent interpretations of narrow, variable absorption lines detected in some Type Ia supernovae suggest that their progenitors are surrounded by dense, circumstellar material. Similar variations detected in the symbiotic recurrent nova…

High Energy Astrophysical Phenomena · Physics 2016-02-03 Richard A. Booth , Shazrene Mohamed , Philipp Podsiadlowski

The outburst cycles of black hole X-ray transients are now generally understood as caused by a thermal instability in the accretion disk, the same mechanism as in dwarf novae outbursts. During quiescence the accretion occurs via a cool disk…

Astrophysics · Physics 2009-11-06 Emmi Meyer-Hofmeister , Friedrich Meyer

The tomographic method "Physical Parameter Eclipse Mapping" is a tool to reconstruct spatial distributions of physical parameters (like temperatures and surface densities) in accretion discs of cataclysmic variables. After summarizing the…

Astrophysics · Physics 2007-05-23 Sonja Vrielmann