Related papers: Superhumps and their Amplitudes
We review the theory and observations related to the ``superhump'' precession of eccentric accretion discs in close binary sytems. We agree with earlier work, although for different reasons, that the discrepancy between observation and…
We report photometric and spectroscopic observations and analysis of the 2019 superoutburst of TCP J21040470+4631129. This object showed a 9-mag superoutburst with early superhumps and ordinary superhumps, which are the features of WZ…
We report time-resolved CCD photometry of the cataclysmic variable EG Aquarii during the 2006 November outburst During the outburst, superhumps were unambiguously detected with a mean period of 0.078828(6) days, firstly classifying the…
We report on time-resolved photometry of the superoutburst of an SU UMa-type dwarf nova, SDSS J013701.06-091234.9 in 2003 December-2004 January. The obtained light curves definitely show superhumps with a period of 0.056686 (12) d, which is…
WZ Sge-type stars are an extreme subclass of dwarf novae characterised by very rare, large-amplitude superoutbursts. Within the disc instability model (DIM), such events are explained as being triggered by enhanced mass transfer from the…
The properties of the aperiodic brightness variability for the dwarf nova HL CMa are considered. The variability of the system HL CMa is shown to be suppressed at frequencies above $7\times10^{-3}$Hz. Different variability suppression…
In the first days of WZ Sge-type dwarf nova (DN) outbursts, the 2:1 resonance induces a spiral arm structure in the accretion disk, which is observed as early superhumps in optical light curves. This paper reports our optical observations…
Planetary-mass objects and brown dwarfs at the transition ($\rm{T}_{eff}\sim1300$\,K) from relatively red L dwarfs to bluer mid-T dwarfs show enhanced spectrophotometric variability. Multi-epoch observations support atmospheric…
We examine published observations of dwarf nova oscillations (DNOs) on the rise and decline of outbursts and show that their rates of change are in reasonable agreement with those predicted from the magnetic accretion model. We find…
We report follow-up observations of the Sloan Digital Sky Survey Cataclysmic Variable SDSS J210014.12+004446.0 (hereafter SDSS J2100). We obtained photometry and spectroscopy in both outburst and quiescent states, providing the first…
We consider accretion discs in close binary systems. We show that heating of a disc at the impact point of the accretion stream contributes significantly to the local energy budget at its outer edge. As a result the thermal balance relation…
We found that the SU UMa-type dwarf nova NY Ser in the period gap [orbital period 0.097558(6) d] showed standstills twice in 2018. This is the first clear demonstration of a standstill occurring between superoutbursts of an SU UMa-type…
We studied the Kepler light curves of three SU UMa-type dwarf novae. Both the background dwarf nova of KIC 4378554 and V516 Lyr showed a combination of precursor-main superoutburst, during which superhumps always developed on the fading…
We present photometry obtained during the 2012 May and September outbursts of the frequently outbursting dwarf nova, V1227 Her. Superhumps were present in both cases with a peak-to peak amplitude of up to 0.28 mag, showing these events to…
We use recent progress in simulating the production of magnetohydrodynamic jets around black holes to derive the cosmic spin history of the most massive black holes, with masses >~10^8 Msol. Assuming the jet efficiency depends on spin a, we…
We construct Super-Eddington Slim Disks models around both stellar and super-massive black holes by allowing the formation of a porous layer with a reduced effective opacity. We show that at high accretion rates, the inner part of the disks…
We report unfiltered photometry of BG Arietis (= SDSS J015151.87+140047.2) in 2009 and 2010 which shows the presence of superhumps with peak-to-peak amplitude of up to 0.36 magnitudes showing this to be an SU UMa type dwarf nova. The…
We report on time-resolved photometry of the 2005 July superoutburst of the dwarf nova, 2QZ J021927.9-304545. The resultant light curves showed conspicuous superhumps with a period of 0.081113(19) days, confirming the SU UMa nature of the…
We present our spectroscopic observations of V455 Andromedae during the 2007 superoutburst. Our observations cover this superoutburst from around the optical peak of the outburst to the post-superoutburst stage. During the early superhump…
We have studied the SC (short cadence) Kepler light curve of an SU UMa star, V1504 Cyg, which extends for a period of about 630 d. All superoutbursts in V1504 Cyg have turned out to be of the precursor-main type and the superhump first…