Related papers: Coherent brightness modulations in the dwarf nova …

EX Dra is a long-period eclipsing dwarf nova with $\sim2-3$ mag amplitude outbursts. This star has been monitored photometrically from November, 2009 to March, 2016 and 29 new mid-eclipse times were obtained. By using new data together with…

Photometric observations of V4633 Sgr (Nova Sagittarii 1998) during 1998-2005 reveal the presence of a stable photometric periodicity at P1=180.8 min which is probably the orbital period of the underlying binary system. A second period was…

We present high speed photometric observations of 20 faint cataclysmic variables, selected from the Sloan Digital Sky Survey and Catalina catalogues. Measurements are given of 15 new directly measured orbital periods, including four…

We report on phase-resolved optical spectroscopy and photometry in the R and B bands of the white dwarf candidate ZTF 185139.81+171430.3. The source has been reported to be variable with a large amplitude of close to 1 magnitude, in the R…

We report the results from the temporal and spectral analysis of an XMM-Newton observation of Nova Centauri 1986 (V842 Cen). We detect a period at 3.51$\pm$0.4 h in the EPIC data and at 4.0$\pm$0.8 h in the OM data. The X-ray spectrum is…

Time-resolved observations of a 6' x 6' field, containing the position error boxes of the X-ray source 1WGA J1958.2+3232, were performed in June 1999 with the 91 cm Catania telescope, equipped with a Photon Counting Intensified CCD. 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 present a comprehensive study of Z CVn, an RR Lyrae star that shows long-term cyclic variations of its pulsation period. A possible explanation suggested from the shape of the O-C diagram is the light travel-time effect, which we…

We report the identification of cyclical changes in the orbital period of the eclipsing dwarf nova Z Cha. We used times of mid-eclipse collected from the literature and our new eclipse timings to construct an observed-minus-calculated…

The quasi-periodic feature of 1-10 years exhibited in pulsar timing noise has not been well understood since 1980. The recently demonstrated correlation between timing noise and variation of pulse profile motivates us to further investigate…

From an examination of ~18,000 Kepler light curves of K- and M-stars we find some 500 which exhibit rotational periods of less than 2 days. Among such stars, approximately 50 show two or more incommensurate periodicities. We discuss the…

Over the past few years monitoring programs have shown ultra cool dwarfs (UCDs) to be photometrically variable. Of the 60 sources monitored in the field and some 120 monitored in clusters, about 40% show variability in both cases. For mid…

We analyse four light curves obtained at high time resolution (~ 0.1 s) with the 11-m Southern African Large Telescope, at the ends of two normal outbursts and one superoutburst of the dwarf nova VW Hyi. All of these contain at least some…

We present our results on two Z Cam stars: Z Cam and AT Cnc. We apply observational data for the periods that cover the states of outbursts and standstills, which are typical for this type of objects. We report an appearance of periodic…

The AM Canum Venaticorum (AM CVn) binaries are a rare group of ultra-short period, mass-transferring white dwarf binaries, some of which may be Type Ia supernova progenitors. More than a third of the total known population of AM CVn…

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 report detailed follow-up observations of the cataclysmic variable HS2331+3905, identified as an emission-line object in the Hamburg Quasar Survey. An orbital period of 81.08min is unambiguously determined from the detection of eclipses…

We present X-ray light curves of Cygnus X-3 as measured by the recently launched AstroSat satellite. The light curve folded over the binary period of 4.8 hours shows a remarkable stability over the past 45 years and we find that we can use…

We analyzed the Kepler long cadence data of KIC 7524178 (=KIS J192254.92+430905.4), and found that it is an SU UMa-type dwarf nova with frequent normal outbursts. The signal of the negative superhump was always the dominant one even during…

We report the results of photometry of the intermediate polar V647 Aur. Observations were obtained over 42 nights in 2012 and 2013. The total duration of the observations was 246 h. We clearly detected three oscillations with periods of…