Related papers: Long-term photometric behaviour of the eclipsing Z…

Dwarf novae are semi-detached binaries, where a white dwarf accretes material from a cool main-sequence companion via an accretion disk, and are known for their intermittent outbursts, making them key systems for studying accretion physics.…

We present the analysis results of an eclipsing cataclysmic variable (CV) V729 Sgr, based on our observations and AAVSO data. Some outburst parameters were determined such as outburst amplitude ($A_{n}$) and recurrence time ($T_{n}$), and…

We report the discovery of a new dwarf nova and our observations of its first confirmed superoutburst during 2009 October. The outburst amplitude was 6 magnitudes. The main outburst lasted 17 days and was followed 4 days later by a…

We present the light curve of HS 0229+8016 between 2006 and 2019 which shows that the star varies between mag 13.4 and 15.1. There were episodes lasting up to hundreds of days during which distinctive 0.6 mag cyclic variations were…

We show that the disc instability model can reproduce all the observed properties of Z Cam stars if the energy equation includes heating of the outer disc by the mass-transfer stream impact and by tidal torques and if the mass-transfer rate…

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…

Analysis of observations of the SU UMa-type dwarf nova, CP Dra, between February 2001 and April 2009 has revealed 15 outbursts, at least eight of which were superoutbursts. The supercycle length is 230+/-56 d. We report photometry of the…

Nova-like variables are high-accretion-rate cataclysmic variables (CVs) that, in contrast to dwarf novae, do not undergo outbursts caused by thermal-viscous instability. However, a small group of nova-likes, classified as AH Pic-type stars,…

We present a new study of the Z~Cam-type eclipsing cataclysmic variable AY~Piscium with the aim of determining the fundamental parameters of the system and the structure of the accretion flow therein. We use time-resolved photometric…

The secular variation in the interval of outbursts in the following six Z Cam-type dwarf novae (including the subtype IW And-type) is investigated: Z Cam, RX And, AH Her, HL CMa, SY Cnc, and WW Cet. An analysis using the $O-C$ diagram shows…

AH Her is a Z Cam-type dwarf nova with an orbital period of ~ 0.258 d. Dwarf nova oscillations and long-period dwarf nova oscillations have been detected, but no quasi-periodic oscillations (QPOs) and negative superhumps (NSHs) have been…

We observed the ROSAT-selected eclipsing dwarf nova GY Cnc (=RX J0909.8+1849) during the 2001 November outburst. We refined the orbital period to be 0.17544251(5) d. The fading portion of the outburst was indistinguishable from those of…

We have observed YZ Cnc at two day intervals from 6 to 24 April 1998, covering two full outburst cycles. The 0.1-2.4 keV flux is lower during optical outburst than in quiescence, and lowest at the end of the outburst. The decline of the…

During the British Astronomical Association (BAA) 2022 campaign, 27436 photometric observations of the dwarf nova (DN) CG Draconis were made, with 106 eclipses recorded. This work summarizes the new data available and provides updated…

Several brief outbursts were detected in the dwarf nova V1316 Cyg during 2005. These events have an average amplitude of 1.4 magnitude and a duration of <1 to 2 days. Whilst no outburst period could be confirmed, the shortest period between…

We report unfiltered photometry during the first confirmed superoutburst of the recently discovered dwarf nova, SDSS J073208.11+413008.7 and conclude that it is a member of the SU UMa family. At its brightest, the star was magnitude 15.7.…

A CCD photometry of the dwarf nova MASTER OT J172758.09 +380021.5 was carried out in 2019 during 134 nights. Observations covered three superoutbursts, five normal outbursts and quiescence between them. The available ASASSN and ZTF data for…

We show that if the dwarf-nova disc instability model includes the effects of heating by stream impact and tidal torque dissipation in the outer disc, the calculated properties of dwarf-nova outbursts change considerably, and several…

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…

Using VSNET, VSOLJ, ASAS-SN and ATLAS observations, I found that the Z Cam star PY Per spent a long, faint low state reaching 19.1 mag at least between 2022 June and November. No dwarf nova outburst was recorded during this interval. TESS…