Related papers: IM Normae: The Death Spiral of a Cataclysmic Varia…
The March 2011 outburst of the poorly-studied cataclysmic variable NSV 1436 offered an opportunity to decide between dwarf nova and recurrent nova classifications. We use seven daily observations in the X-ray and UV by the Swift satellite,…
We performed a detailed analysis of extensive photometric observations of a sample of most active dwarf novae, that is SU UMa stars which are characterised by supercycle lengths shorter than 120 days. We found the observational evidence…
We present time-resolved optical spectroscopy of the dwarf nova CSS100603:112253-111037. Its optical spectrum is rich in helium, with broad, double-peaked emission lines produced in an accretion disc. We measure a line flux ratio…
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 report the discovery of a new catacysmic variable system, RXJ051541+0104.6. The optical spectrum has a blue continuum with superposed H~I and He~I and II emission lines. The soft X-ray spectrum is well fit with a 50~eV black body. The…
We announce the identification of a new cataclysmic variable star in the field of the Kepler Mission, KIC J192410.81+445934.9. This system was identified during a search for compact pulsators in the Kepler field. High-speed photometry…
We have modeled the unusual orbital light curve of V1494 Aquilae (Nova Aquilae 1999 No.2) and found that such an unusual orbital light curve can be reproduced when there exist two-armed, spiral shocks on the accretion disk. V1494 Aql is a…
An XMM-Newton observation of the nearby "pre-cataclysmic" short-period (P_orb = 3.62 hr) binary QS Vir (EC 13471-1258) revealed regular narrow X-ray eclipses when the white dwarf passed behind its M2-4 dwarf companion. The X-ray emission…
We present an analysis of photometric observations of the eclipsing novalike variable DW UMa made by the CBA consortium between 1999 and 2015. Analysis of 372 new and 260 previously published eclipse timings reveals a 13.6 year period or…
We have studied the short-cadence Kepler public light curves of SU UMa stars, V344 Lyr and V1504 Cyg extending over a period of more than two years by using power spectral analysis. We determined the orbital period of V344 Lyr to be…
We investigated the optical light curve of T Pyx during its 2011 outburst through compiling a database of SMEI and AAVSO observations. The SMEI light curve, providing unprecedented detail with high cadence data during t=1.5-49 days…
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…
Recurrent novae (RNe) are cataclysmic variables with two or more nova eruptions within a century. Classical novae (CNe) are similar systems with only one such eruption. Many of the so-called 'CNe' are actually RNe for which only one…
We present a theoretical light curve model of the recurrent nova M31N 2008-12a, the current record holder for the shortest recurrence period (1 yr). We combined interior structures calculated using a Henyey-type evolution code with…
Context: Optical nova lightcurves often have structures, such as rapid declines and recoveries, due to nebular or dusty phases of the ejecta. Nova Cygni 2006 (V2362 Cyg) underwent an unusual brightening after an early rapid decline. The…
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…
I observed the very fast nova V838 Her (Nova Her 1991, optical peak at 5-5.4 mag) during the fading phase of the nova eruption in 1991. I detected eclipses, for the first time in the world in any nova during eruption, and the epochs of the…
We report on our second campaign to search for old nova shells around cataclysmic variables (CVs). Our aim was to test the theory that nova eruptions cause cycles in the mass transfer rates of CVs. These mass transfer cycles change the…
We report extensive photometry of the dwarf nova V660 Herculis. During our campaign, lasting from August 2003 to November 2004, we recorded one bright eruption which turned out to be a superoutburst lasting about 15 days and having…
We have carried out a new photometric V,Rc study of 12 protoplanetary nebulae, objects in the short-lived transition between the AGB and PN phases of stellar evolution. These had been the subjects of an earlier study, using data from…