Related papers: Faint-state transitions in the SW Sextantis nova-l…

CCD UBVRI photometry is presented for type IIn SN 2005kd. The maximum luminosity exceeded Mv=-19.8, and SN remained brighter than -18 mag for about 400 days. While overall photometric evolution is quite similar to SN 1997cy, SN 2005kd shows…

We present the first results of a photometric survey of poorly studied nova remnants in the Northern Hemisphere. The main results are as follows: DM Gem shows a modulation at 0.123 d (probably linked to the orbit) and rapid variations at…

We present a detailed study of a transient in the center of SDSS1115+0544 based on the extensive UV, optical, mid-IR light curves (LC) and spectra over 1200 days. The host galaxy is a quiescent early type galaxy at $z$ = 0.0899 with a…

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…

During 2006 November an outburst of the dwarf nova AW Sge was observed using CCD photometry. This revealed 0.25 magnitude superhumps confirming it to be a superoutburst, possibly only the second confirmed such outburst of this star. The…

From a large observing campaign, we found that nearly all non- or weakly magnetic cataclysmic variables (CVs) in the orbital period range between 2.8 and 4 hours are of SW Sex type and as such experience very high mass transfer rates. The…

We report extensive photometry of the dwarf nova KS UMa throughout its 2003 superoutburst till quiescence. During the superoutburst the star displayed clear superhumps with a mean period of Psh = 0.070092(23) days. In the middle stage of…

The prototype of accreting, pulsating white dwarfs (GW Lib) underwent a large amplitude dwarf nova outburst in 2007. We used ultraviolet data from GALEX and ground-based optical photometry and spectroscopy to follow GW Lib for three years…

Since the large amplitude 2007 outburst which heated its accreting, pulsating white dwarf, the dwarf nova system GW Librae has been cooling to its quiescent temperature. Our Hubble Space Telescope ultraviolet spectra combined with…

We report the detection of a faint old stellar system at $(\alpha,\delta)=(194.29^\circ,~34.32^\circ)$ (SDSS J1257+3419), based on the spatial distribution of bright red-giant branch stars in the Sloan Digital Sky Survey Data Release 4.…

We report on the results of the QW Ser campaign which has been continued from 2000 to 2003 by the VSNET collaboration team. Four long outbursts and many short ones were caught during this period. Our intensive photometric observations…

Following the pulsation spectrum of a white dwarf through the heating and cooling involved in a dwarf nova outburst cycle provides a unique view of the changes to convective driving that take place on timescales of months versus millenia…

We report follow-up spectroscopy of 29 cataclysmic variables from the Sloan Digital Sky Survey (SDSS), 22 of which were discovered by SDSS and seven other previously known systems that were recovered in SDSS. The periods for 16 of these…

We present the results of the analysis of the SRG/ART-XC observation of the Supergiant Fast X-ray Transient IGR J16195-4545 performed on March 3, 2021. Six bright flares are present in the light curve, with no significant change in hardness…

Using a recent Chandra ACIS observation of the eclipsing cataclysmic variable (CV) V1460 Her (2MASS J16211735+4412541) with a fast-rotating ($P_{\rm spin} = 38.9$~s) white dwarf, we estimated a flux $F_{0.5-7 {\rm keV}}^{\rm abs} = (1.9\pm…

We present an analysis of CCD photometric observations of the eclipsing novalike cataclysmic variable DW UMa obtained in two different luminosity states: high and intermediate. The star presents eclipses with very different depth: ~1.2 mag…

We present time-resolved spectroscopy and photometry of the dwarf nova SBSS 1108+574, obtained during the 2012 outburst. Its quiescent spectrum is unusually rich in helium, showing broad, double-peaked emission lines from the accretion…

We report on time-resolved CCD photometry of four outbursts of a short-period SU UMa-type dwarf nova, V844 Herculis. We successfully determined the mean superhump periods to be 0.05584(64) days, and 0.055883(3) for the 2002 May…

We report on 15 years of VLA monitoring of the gravitational lens B0957+561 at 6 cm. Since our last report in 1992, there have been 32 additional observations, in which both images have returned to their quiescent flux density levels and…

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…