Related papers: Observations of Five Southern-Hemisphere Cataclysm…

Cataclysmic variables were long considered to be close binaries consisting of a white dwarf and a Roche-lobe-filling, near-zero-age main-sequence (ZAMS) red or brown dwarf. Recent massive surveys have uncovered an increasing number of…

We report time-series photometry for 16 variable stars located in the central part of the globular cluster NGC 6752. The sample includes 13 newly identified objects. The precision of our differential photometry ranges from 1 mmag at V=14.0…

I conducted photometric observations of the cataclysmic variable LAMOST J035913.61+405035.0 and discovered previously unknown eclipses. During these observations, I recorded 14 eclipses over two groups of nights separated by 13 months. I…

We present VLT spectroscopy and NTT photometry of the faint cataclysmic binary SDSS J003941.06+005427.5. This object shows triple-peaked H-alpha emission with all three peaks variable in both strength and velocity. We measure an orbital…

We report on the discovery of J0644+3344, a bright deeply eclipsing cataclysmic variable (CV) binary. Spectral signatures of both binary components and an accretion disk can be seen at optical wavelengths. The optical spectrum shows broad H…

We report follow-up studies of 35 recently-discovered cataclysmic variables (CVs), 32 of which were found in large, automated synoptic sky surveys. The objects were selected for observational tractability. For 34 of the objects we present…

We present the results of photometric observations of SDSS J080434.20+510349.2 in its low state and during an outburst and spectroscopy during the outburst. We found such peculiarities as a long-term outburst with amplitude probably not…

We present time-series VLT spectroscopy and NTT photometry of the cataclysmic variable SDSS J220553.98+115553.7, which contains a pulsating white dwarf. We determine a spectroscopic orbital period of 82.825 +/- 0.089 min from velocity…

We present the results of a photometric survey for variable stars in the nearby globular cluster M5. A 14.8x22.8 arcmin^2 field centered on the cluster was monitored for a total of 37 hours with a CCD camera mounted on the 1.0-m Swope…

(Abridged). The cataclysmic binary V405 Peg, originally discovered as ROSAT Bright Source (RBS) 1955 (= 1RXS J230949.6+213523), shows a strong contribution from a late-type secondary star in its optical spectrum, which led Schwope et al. to…

From a set of thirteen cataclysmic binaries that were discovered in the Swift Burst Alert Telescope (BAT) survey, we conducted time-resolved optical spectroscopy and/or time-series photometry of eleven, with the goal of measuring their…

We present here results of an optical spectroscopic study of a new Cataclysmic Variable SDSS J001856.93+345444.3. We demonstrate that the most probable value of the orbital period of the system is Porb = 0.6051 \pm 0.022 days (=14.5226…

We report the identification and follow-up of the transient SRG 062340.2-265715 detected with both instruments on board the Spektrum-Roentgen-Gamma mission. Optical spectroscopy of the G=12.5 counterpart firmly classifies the object as a…

NSV 1907, formerly listed as an irregular variable in variability catalogues, was classified as an Algol-type eclipsing binary in the Catalina Surveys Periodic Variable Star Catalogue. We have identified NSV 1907 as an ultraviolet (UV)…

Photometric and spectroscopic observations of the candidate cataclysmic variable KUV03580+0614, independently found from the Hamburg survey as HS0357+0614, reveal this to be a cataclysmic variable with an orbital period of 3.4 hrs. CVs with…

We present optical photometric and spectroscopic observations of two Cataclysmic Variables (CVs), namely RBS 0490 and SDSS J075939.79+191417.3. The optical variations of RBS 0490 have been found to occur at the period of 1.689$\pm$0.001 hr…

We present optical spectroscopy of nine cataclysmic binary stars, mostly dwarf novae, obtained primarily to determine orbital periods Porb. The stars and their periods are LX And, 0.1509743(5) d; CZ Aql, 0.2005(6) d; LU Cam, 0.1499686(4) d;…

We report on follow-up spectroscopy and photometry of the cataclysmic variable candidate HS0907+1902 selected from the Hamburg Quasar Survey. B, V, and R photometry obtained during the first observed outburst of HS0907+1902 (V~13) reveals…

We conducted a spectroscopic and photometric study of SDSS J075653.11+085831. X-ray observations were also attempted. We determined the orbital period of this binary system to be 3.29 hr. It is a deep eclipsing system, whose spectra shows…

We present time-resolved optical spectroscopy and photometry of four relatively bright (V~14.0-15.5) long-period cataclysmic variables (CVs) discovered in the Hamburg Quasar Survey: HS0139+0559, HS0229+8016, HS0506+7725 and HS0642+5049.…