HV Virginis and WZ Sge-Type Dwarf Novae

Katô, Takeo; Sekine, Yoshiyuki; Hirata, Ryuko

doi:10.1093/pasj/53.6.1191

Cited by 97 publications

(141 citation statements)

References 268 publications

Supporting

Mentioning

132

Contrasting

Order By: Relevance

“…Although these modulations were detected independently by different groups Mendelson et al 1992;Leibowitz et al 1994 and our group), the distinction of these modulations from (ordinary) superhumps should await yet another object. Our result of HV Vir in 1992 was published in Kato et al (2001) following modern interpretation.…”

Section: Early Superhumpsmentioning

confidence: 57%

WZ Sge-type dwarf novae

Katô

2015

Publications of the Astronomical Society of Japan

Self Cite

161

View full text Add to dashboard Cite

We have summarized the current understanding and recently obtained findings about WZ Sge-type dwarf novae. We also reviewed the historical development of the understanding of these objects, provided the modern criteria, and reviewed the past research in relation to superhumps, early superhumps and the outburst mechanism. We regard that the presence of early superhumps (reflecting the 2:1 resonance) and long or multiple rebrightenings are the best distinguishing properties of WZ Sge-type dwarf novae. We provided the updated list of nearly 100 WZ Sge-type dwarf novae mainly based on the data obtained by the VSNET Collaboration up to Kato et al. (2015) and discussed the statistics. We could detect early superhumps with amplitude larger than 0.02 mag in 63% of the studied WZ Sge-type dwarf novae, which makes early superhumps a useful distinguishing feature for WZ Sge-type dwarf novae. Theoretical light curves of early superhumps generally appear to reproduce the existence of many low-amplitude objects, supporting the geometrical origin of early superhumps. Using the recently developed method of measuring mass ratios using developing phase of superhumps (stage A superhumps), we showed that there is a linear relation between the period variation of superhumps and the mass ratio in WZ Sge-type objects. By using this relation, we were able to draw an evolutionary picture of a large number of WZ Sge-type and identified the type of outburst to be an evolutionary sequence: type C → D → A → B → E, with some outliers for type-B objects. The duration of stage A (evolutionary phase) of superhumps is also well correlated with the estimated mass ratios. By using mass ratios from stage A superhumps and durarion of stage A, we have been able to identify best candidates for period bouncers.

show abstract

Section: Early Superhumpsmentioning

confidence: 57%

WZ Sge-type dwarf novae

Katô

2015

Publications of the Astronomical Society of Japan

Self Cite

161

View full text Add to dashboard Cite

show abstract

“…The origin of unique light variations, as well as their evolutionary status, are still in debate (e.g., Osaki, Meyer 2003;Nakata et al 2014; see Kato 2015 for a review). Their observational properties are that (1) the amplitude of the superoutburst is large, exceeding ∼ 6 mag (Howell et al 1995), (2) the interval between the successive superoutbursts (supercycle) is unusually long, typically with a time scale of decades (Kato et al 2001), (3) modulations with double-peaked profiles called early superhumps are observed in the early phase of the superoutburst (Kato 2002), and (4) after the end of the plateau stage, single or multiple rebrightenings are observed (Imada et al 2006). Among them, properties (3) and (4) are considered to be unique to WZ Sge-type dwarf novae and to be the defining characteristics (see Kato 2015).…”

Section: Introductionmentioning

confidence: 99%

Unexpected superoutburst and rebrightening of AL Comae Berenices in 2015

Kimura¹,

Katô²,

Imada³

et al. 2016

Publications of the Astronomical Society of Japan

Self Cite

View full text Add to dashboard Cite

In 2015 March, the notable WZ Sge-type dwarf nova AL Com exhibited an unusual outburst with a recurrence time of ∼1.5 yr, which is the shortest interval of superoutbursts among WZ Sge-type dwarf novae. Early superhumps in the superoutburst light curve were absent, and a precursor was observed at the onset of the superoutburst for the first time in WZ Sge-type dwarf novae. The present superoutburst can be interpreted as a result of the condition that the disk radius barely reached the 3:1 resonance radius, but did not reach the 2:1 resonance one. Ordinary superhumps immediately grew following the precursor. The initial part of the outburst is indistinguishable from those of superoutbursts of ordinary SU UMa-type dwarf novae. This observation supports the interpretation that the 2:1 resonance suppresses a growth of ordinary superhumps. The estimated superhump period and superhump period derivative are P sh = 0.0573185(11) d and P dot = +1.5(3.1) × 10 −5 , respectively. These values indicate that the evolution of ordinary superhumps is the same as that in past superoutbursts with much larger extent. Although the light curve during the plateau stage was typical for an SU UMa-type dwarf nova, this superoutburst showed a rebrightening, together with a regrowth of the superhumps. The overall light curve of the rebrightening was the almost the same as those observed in previous rebrightenings. This implies that the rebrightening type is inherent in the system.

show abstract

“…Send offprint requests to: T. Kato, e-mail: tkato@kusastro.kyoto-u.ac.jp A large fraction of such confusions turned out to be SU UMa-type dwarf novae or WZ Sge-type dwarf novae (Kato et al 2001b). SU UMa-type dwarf novae are a subclass of DNe.…”

Section: Introductionmentioning

confidence: 99%

“…The object was even proposed to be a nova in the Galactic halo. From distant nova candidates, Kato et al (2001b) selected V359 Cen as a candidate for a rarely outbursting dwarf nova. A finding chart of the proposed quiescent counterpart was presented in Duerbeck (1987).…”

Section: Introductionmentioning

confidence: 99%

The nature of V359 Centauri revealed: New long-period SU UMa-type dwarf nova

Katô

Stubbings²,

Nelson

et al. 2002

A&A

View full text Add to dashboard Cite

Abstract. We detected four outbursts of V359 Cen (possible nova discovered in 1939) between 1999 and 2002. Time-resolved CCD photometry during two outbursts (1999 and 2002) revealed that V359 Cen is actually a long-period SU UMa-type dwarf nova with a mean superhump period of 0.08092(1) d. We identified its supercycle length as 307-397 d. This secure identification of the superhump period precludes the previously supposed possibility that V359 Cen could be related to a WZ Sge-type system with a long persistence of late superhumps. The outburst characteristics of V359 Cen are, however, rather unusual in its low occurrence of normal outbursts.

show abstract

HV Virginis and WZ Sge-Type Dwarf Novae

Cited by 97 publications

References 268 publications

WZ Sge-type dwarf novae

WZ Sge-type dwarf novae

Unexpected superoutburst and rebrightening of AL Comae Berenices in 2015

The nature of V359 Centauri revealed: New long-period SU UMa-type dwarf nova

Contact Info

Product

Resources

About