Related papers: The Unusual Cataclysmic Binary Star RBS 0490 and t…

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…

(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…

We find that the ROSAT source 1RXS J105010.3-140431 is a cataclysmic variable with orbital period of 88.6 minutes and a spectrum closely resembling WZ Sge. In particular, emission lines are flanked by Stark-broadened absorption wings…

We give an identification summary and results of polarimetric, photometric and spectroscopic follow-up observations of new, X-ray bright cataclysmic variables. These were identified as optical counterparts of high galactic latitude sources…

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 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…

We present high-speed, three-colour photometry of the eclipsing cataclysmic variable SDSS J170213.26+322954.1 (hereafter SDSS J1702+3229). This system has an orbital period of 2.4 hours, placing it within the ``period gap'' for cataclysmic…

We have discovered a new high proper motion cataclysmic variable (CV) in the SUPERBLINK proper motion survey, which is sensitive to stars with proper motions greater than 40 mas/yr. This CV was selected for follow-up observations as part of…

We report the discovery of a new bright (V$\sim$12.6) cataclysmic variable star identified with the ROSAT X-ray source RX J1643.7+3402. Spectroscopic and photometric observations show it to be a novalike variable sharing some of the…

The spectrum of the recently discovered cataclysmic variable star (CV) ASAS-SN 13cl shows that a secondary star with spectral type K4 (+- 2 subclasses) contributes roughly half the optical light. The radial velocities of the secondary are…

We report on optical spectroscopic and photometric follow-up observations of the eROSITA discovered transient SRGt 062340.2-265751 and show that it displays the characteristics of a nova-like cataclysmic variable (CV), with possible…

We use the ROSAT North Ecliptic Pole (NEP) survey to construct a small, but purely X-ray flux-limited sample of cataclysmic variable stars (CVs). The sample includes only 4 systems, 2 of which (RX J1715.6+6856 and RX J1831.7+6511) are new…

The space density of the various classes of cataclysmic variables (CVs) could only be weakly constrained in the past. Reasons were the small number of objects in complete X-ray flux-limited samples and the difficulty to derive precise…

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…

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 the results of our X-ray, ultraviolet, and optical follow-up campaigns of 1RXS J165424.6-433758, an X-ray source detected with the \textit{Swift} Deep Galactic Plane Survey (DGPS). The source X-ray spectrum (\textit{Swift} and…

We report a photometric and spectroscopic study of the peculiar cataclysmic variable SDSS 1507+52. The star shows very deep eclipses on the 67 minute orbital period, and those eclipses are easily separable into white-dwarf and hot-spot…

We present spectroscopy and orbital periods Porb of four relatively little-studied cataclysmic variable stars. The stars and their periods are: AF Cam, Porb = 0.324(1) d (the daily cycle count is slightly ambiguous); V2069 Cyg (= RX…

The Catalina Real Time Survey (CRTS) has found over 500 cataclysmic variable (CV) candidates, most of which were previously unknown. We report here on followup spectroscopy of 36 of the brighter objects. Nearly all the spectra are typical…

We report observations of the known cataclysmic variable star (CV) V704 And, and also confirm that the optical counterpart of the ROSAT Galactic Plane Survey source RX J2338+431 is a heretofore-neglected CV. Photometric and spectroscopic…