Related papers: Unusual stunted outbursts in the nova-like variabl…

We present photometry and spectroscopy of the suspected cataclysmic variable (CV) Lanning 386. We confirm that it is a CV, and observe deep eclipses, from which we determine the orbital period Porb to be 0.1640517 +- 0.0000001 d (= 3.94 h).…

We find from high speed photometry of the Sloan Digital Survey cataclysmic variable candidate SDSS J161033.64-010223.3 that it has a double humped modulation, which is probably orbital, with a period of 80.52 minutes, and shows strong ZZ…

We observed ASASSN-19ax during the long outburst in 2021 September-October. The object has been confirmed to be an SU UMa-type dwarf nova with a superhump period of 0.1000-0.1001 d. This object showed two post-superoutburst rebrightenings…

A radial velocity study of the cataclysmic variable ES Dra (PG 1524+622) is presented. ES Dra is found to have an orbital period of 0.17660 \pm 0.00006 d (4.2384 \pm 0.0014 h). The mass-losing secondary star of ES Dra is detectable in the…

We present results from the XMM observations of the dwarf nova YZ Cnc in a quiescent state. We have performed a detailed time series analysis of the resulting light curves. Unusually, we do not detect any orbital modulation in the UV, with…

There are several peculiar long-period dwarf-nova like objects, which show rare, low-amplitude outbursts with highly ionized emission lines. 1SWASP J162117$+$441254, BD Pav, and V364 Lib belong to this kind of objects. Some researchers even…

We report the discovery of a new, non-eclipsing SU UMa-type dwarf nova, HS 2219+1824. Photometry obtained in quiescence (V ~ 17.5) reveals a double-humped light curve from which we derive an orbital period of ~ 86.2 min. Additional…

We present a detailed study of the MASTER OT J030227.28+191754.5 outburst in 2021-2022, reaching an amplitude of 10.2 mag and a duration of 60 d. The detections of (1) the double-peaked optical emission lines, and (2) the early and ordinary…

We report on our photometric observations of the 2016 superoutburst of ASASSN-16eg. This object showed a WZ Sge-type superoutburst with prominent early superhumps with a period of 0.075478(8) d and a post-superoutburst rebrightening. During…

The defining characteristic of Z Cam stars are standstills in their light curves. Some Z Cams exhibit atypical behaviour by going into outburst from a standstill. It has previously been suggested that UY Pup had been a Z Cam star, but it…

We report unfiltered photometry of SDSS J112003.40+663632.4 during the 2011 February outburst which revealed the presence of superhumps with peak-to-peak amplitude of up to 0.22 magnitudes showing this to be an SU UMa type dwarf nova. The…

We report a photometric study of the WZ Sagittae-type dwarf nova PQ Andromedae. The light curve shows strong (0.05 mag full amplitude) signals with periods of 1263(1) and 634(1) s, and a likely double-humped signal with P=80.6(2) min. We…

We report follow-up observations of five cataclysmic variable candidates from LAMOST published by Hou et al. (2020). LAMOST J024048.51+195226.9 is the most unusual of the five; an early-M type secondary star contributes strongly to its…

We report CCD photometry and spectroscopy during 2006 outburst of the dwarf nova SDSS J102146.44+234926.3 (SDSS J1021). The photographic plates from the MAO, SAI and CrAO plate archives, which cover the position of the SDSS J1021, were…

We present simulations of dwarf nova outbursts taking into account realistic variations of the mass loss rate from the secondary. The mass transfer variation has been derived from 20 years of visual monitoring and from X-ray observations…

The Z Cam stars IW And and V513 Cas are unusual in having outbursts following their standstills in contrast to the usual Z Cam behavior of quiescence following standstills. In order to gain further understanding of these little-studied…

Nova V2491 Cyg is one of just two detected pre-outburst in X-rays. The light curve of this nova exhibited a rare "re-brightening" which has been attributed by some as the system being a polar, whilst others claim that a magnetic WD is…

We study the variability of the cataclysmic variable DO Dra, on time-scales of between minutes and decades. The characteristic decay time dt/dm=0.902(3) days/mag was estimated from our 3 nights of CCD R observations. The quiescent data show…

Our photometric monitoring revealed that DW Cnc, which was originally classified as a dwarf nova (V=15--17.5), remained at a bright state of Rc=14.68+/-0.07 for 61 days. In conjunction with optical spectra lacking a strong He II emission…

ASASSN-15cm had been identified as a dwarf nova with an orbital period of 5.0 hours and a hot, luminous secondary of of a spectral type around K2.5 in the previous study. Using the Zwicky Transient Facility (ZTF) data, the Asteroid…