A model for WZ Sge with "standard" values of alpha

Abstract

We present a model for the dwarf nova WZ Sge which does not require assuming unusually and unexplained low values of the viscosity alpha-parameter during exceptionally long quiescent states of this system. We propose that the inner parts of the accretion disc are disrupted by either a magnetic field or evaporation, so that the disc is stable (or very close to being stable) in quiescence, as the mass transfer rate is very low and the disc can sit on the cool, lower branch of the thermal equilibrium curve. Outbursts are triggered by an enhanced mass transfer, which brings the disc into the unstable regime of the standard dwarf nova disc instability model. The resulting eruptions are strongly affected by the irradiation of the secondary star. Our model reproduces very well the recurrence time and the characteristics of the light curve in outburst.

4 pages, 1 postscript figure. Accepted for publication in MNRAS

Cited by in corpus (30)

• The disc instability model of dwarf-novae and low-mass X-ray binary transients
• A review of the disc instability model for dwarf novae, soft X-ray transients and related objects
• The 2001 Superoutburst of WZ Sagittae
• Variable Star Network: World Center for Transient Object Astronomy and Variable Stars
• Is evidence for enhanced mass transfer during dwarf-nova outbursts well substantiated?
• The viscosity parameter alpha and the properties of accretion disc outbursts in close binaries
• Disc instability models for X-ray transients: evidence for evaporation and low alpha-viscosity ?
• The nature of dwarf nova outbursts
• Models of AM CVn star outbursts
• Delays in dwarf novae I: The case of SS Cygni
• Hot white dwarfs and the UV delay in dwarf novae
• A Population of Faint Non-Transient Low Mass Black Hole Binaries
• Dynamical constraints on the component masses of the cataclysmic variable WZ Sge
• Superoutbursts, superhumps and the tidal-thermal instability model
• WZ Sagittae as a DQ Herculis star
• All Quiet in Globular Clusters
• SDSS J080434.20+510349.2: Eclipsing WZ Sge-Type Dwarf Nova with Multiple Rebrightenings
• Keck IR Spectroscopy of WZ Sge: Detection of Molecular Emission from the Accretion Disk
• The 2001 Superoutburst of WZ Sagittae: A Clue to the Dynamics of Accretion Disks
• Time-resolved observations of the short period CV SDSS J123813.73-033933.0
• Magnetically moderated outbursts of WZ Sagittae
• The outburst of a 60 min AM CVn reveals peculiar color evolution: implications for outbursts in long period double white dwarfs
• Secular changes in the quiescence of WZ Sge: the development of a cavity in the inner disk
• Dramatic Spectral Evolution of WZ Sagittae during the 2001 Superoutburst
• Modelling rebrightenings, reflares, and echoes in dwarf nova outbursts
• WZ Sge-Type Star V592 Herculis
• Outbursts in ultracompact X-ray binaries
• The relation between outburst rate and orbital period in low-mass X-ray binary transients
• Long-term monitoring of the short period SU UMa-type dwarf nova, V844 Herculis
• XMM-Newton and Swift observations of WZ Sge: spectral and timing analysis