Bemerkungen zu neueren Veränderlichen

Esch, M.

doi:10.1002/asna.19372641804

Cited by 2 publications

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…EF Peg was originally discovered as a variable star (Hoffmeister, 1935), who suggested the Mira-type classification. Esch (1937) recorded two additional (bright and faint ones) maxima, and derived a period period of 157 d in combination with the maxima recorded by Hoffmeister (1935). However, Sandig (1950) only recorded an apparently nonvariable star of 13.5-14.0 photographic magnitude on 157 plates.…”

Section: Ef Pegmentioning

confidence: 76%

Photometry of the 1991 Superoutburst of EF Pegasi: Super-Quasi-Periodic Oscillations with Rapidly Decaying Periods

Katô¹

2002

Publications of the Astronomical Society of Japan

View full text Add to dashboard Cite

We observed the 1991 October outburst of EF Peg. Prominent superhumps with a period of 0.08705(1) d were observed, qualifying EF Peg as a being long-period SU UMa-type dwarf nova. The superhump period showed a monotonous decrease during the superoutburst, which makes a contrast to the virtually zero period change observed during the 1997 superoutburst of the same object. Large-amplitude, and highly coherent quasi-periodic oscillations (super-QPOs) were observed on October 18, when superhumps were still growing in amplitude. Most strikingly, the QPOs showed a rapid decrease of the period from 18 m to 6.8 m within the 3.2-hr observing run. Such a rapid change in the period has not been observed in any class of QPOs in cataclysmic variables. We propose a hypothesis that the rapid decrease of the QPO period reflects the rapid removal of the angular momentum from an orbiting blob in the accretion disk, via the viscosity in a turbulent disk. A brief comparison is given with the QPOs in Xray binaries, some of which are known to show a similar rapid decrease in the periods.

show abstract

Section: Ef Pegmentioning

confidence: 76%

Photometry of the 1991 Superoutburst of EF Pegasi: Super-Quasi-Periodic Oscillations with Rapidly Decaying Periods

Katô¹

2002

Publications of the Astronomical Society of Japan

View full text Add to dashboard Cite

show abstract

HV Virginis and WZ Sge-Type Dwarf Novae

Katô

Sekine

Hirata

2001

Publications of the Astronomical Society of Japan

131

View full text Add to dashboard Cite

A dwarf nova HV Vir was observed photometrically for eight nights during the outburst in 1992 April -May. The star showed two distinct types of periodic variation: (1) 82.20-min (0.05708 d) double-humped variation with decaying amplitudes during the early stage of the outburst, and (2) 83.80-min (0.05820 d) superhumps in later stages. We attributed the former to "early superhumps", which are only seen in the earliest stage of WZ Sge-type outbursts. The superhump period and evolution of the superhumps, together with general characteristics of the light curve, make HV Vir a typical WZ Sge-type dwarf nova. HV Vir also showed a large increase of the superhump period during the superoutburst. Upon the recognition of the WZ Sge-type nature of an object previously considered as a nova, we present a comprehensive list of candidates for WZ Sge-type dwarf novae, and related systems.

show abstract

Bemerkungen zu neueren Veränderlichen

Cited by 2 publications

References 0 publications

Photometry of the 1991 Superoutburst of EF Pegasi: Super-Quasi-Periodic Oscillations with Rapidly Decaying Periods

Photometry of the 1991 Superoutburst of EF Pegasi: Super-Quasi-Periodic Oscillations with Rapidly Decaying Periods

HV Virginis and WZ Sge-Type Dwarf Novae

Contact Info

Product

Resources

About