Related papers: UY Puppis - A New Anomalous Z Cam Type Dwarf Nova

We have observed dwarf nova oscillations (DNOs) in OY Car during outburst, down through decline and beyond; its behaviour is similar to what we have previously seen in VW Hyi, making it only the second dwarf nova to have DNOs late in…

We present the analysis of hot spot brightness in light curves of the eclipsing dwarf nova IY Ursae Majoris during its normal outburst in March 2013 and in quiescence in April 2012 and in October 2015. Examination of four reconstructed…

HL CMa is a Z Cam-type dwarf nova which was discovered as an Einstein X-ray source. In addition to normal outbursts and standstills, we noticed the presence of "the third" outbursting state. During this period, the star showed weak…

SS Cyg has long been recognized as the prototype of a group of dwarf novae that show only outbursts. However, this object has entered a quite anomalous event in 2021, which at first appeared to be standstill, i.e., an almost constant…

We present our results on two Z Cam stars: Z Cam and AT Cnc. We apply observational data for the periods that cover the states of outbursts and standstills, which are typical for this type of objects. We report an appearance of periodic…

IW And was discovered as a unique blue variable, which spends 72% of time in "inactive" state, and was only occasionally observed in bright or faint states. Although the past spectroscopy confirmed that the object is a cataclysmic variable…

BZ UMa is a cataclysmic variable star whose specific classification has eluded researchers since its discovery in 1968. It has outburst and spectral properties consistent with both U Gem class dwarf novae and intermediate polars. We present…

IX Vel has been considered as one of the prototypical novalike cataclysmic variables with thermally stable accretion disks. Using All-Sky Automated Survey (ASAS-3) and All-Sky Automated Survey for Supernovae (ASAS-SN) observations, I found…

We observed the 2015 July-August long outburst of V1006 Cyg and established this object to be an SU UMa-type dwarf nova in the period gap. Our observations have confirmed that V1006 Cyg is the second established object showing three types…

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…

We search the American Association of Variable Star Observers (AAVSO) archives of the two best studied dwarf novae in an attempt to find light curves for long outbursts that are extremely well-characterized. The systems are U Gem and SS…

We carried out time-resolved $V$-band photometry of DM Lyr during long outbursts in 1996 July and in 1996 February-March at Ouda Station, Kyoto University and at Osaka Kyoiku University. Since superhumps were clearly detected in the light…

We present the 13-year light curve of HW Boo between 2001 May and 2014 May. We identified 12 outbursts, which typically lasted 2 to 5 days, with an amplitude of 2.7 to 3.6 magnitudes. Time resolved photometry during two outbursts revealed…

Photometry of Leo5 = 1H 1025+220 show that it is a dwarf nova of the Z Cam subtype. Two long standstills have been observed in the last five years.

Novalike variables are a subgroup of cataclysmic variables (CVs) that -- unlike dwarf novae -- do not exhibit strong brightenings in their long-term light curves. Variations over time scales of weeks, months or years are mostly restricted…

We studied the IW And star V507 Cyg using ASAS-SN data, ZTF data and our snapshot photometry. The star has been found to be in a long standstill in 2020 May-2022 March (and it still continues now). Such long-lasting standstills have been…

We report results of an extensive world-wide observing campaign devoted to a very active dwarf nova star - IX Draconis. We investigated photometric behaviour of the system to derive its basic outburst properties and understand peculiarities…

We discovered a new deeply eclipsing SU UMa-type dwarf nova, IY UMa, which experienced a superoutburst in 2000 January. Our monitoring revealed two distinct outbursts, which suggest a superoutburst interval of ~800 d, or its half, and an…

We present photometric study of NY Ser, an in-the-gap SU UMa-type nova, in 2002 and 2013. We determined the duration of the superoutburst and the mean superhump period to be 18 d and 0.10458 d, respectively. We detected in 2013 that NY Ser…

We studied the evolution of superhumps in the peculiar SU UMa-type dwarf nova, ER UMa. Contrary to the canonical picture of the SU UMa-type superhump phenomena, the superhumps of ER UMa show an unexpected phase reversal during the very…