Related papers: Decrease in the orbital period of dwarf nova OY Ca…
We have detected coherent oscillations (``dwarf nova oscillations'') in Hubble Space Telescope spectra of the dwarf nova OY Car. The oscillations were seen towards the end of a superoutburst of OY Car. The oscillations are extraordinary…
We present spectroscopy of seven cataclysmic variable stars with orbital periods P(orb) greater than 5 hours, all but one of which are known to be dwarf novae. Using radial velocity measurements we improve on previous orbital period…
We report spectroscopy of the newly discovered SU Ursae Majoris dwarf nova identified with the x-ray source RXS J053234.9+624755. Radial velocities of the H-alpha emission line in the quiescent state give an orbital period of 0.05620(4) d…
We present results of non-simultaneous time-resolved photometric and spectroscopic observations of the little-studied dwarf nova FS Aur in quiescence. The spectrum of FS Aur shows strong and broad emission lines of hydrogen and HeI, and of…
FS Aur is a known dwarf nova with an orbital period of about 85.7 minutes. It has been assumed to be a member of the SU UMa subclass of cataclysmic variables (CVs), but previous searches for superhumps and superoutburst have been…
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…
The spectral and photometric studies of the cataclysmic variable Gaia 19cwm (or ZTF19aamkwxk) have been performed. Based on the analysis of long-term variability, it is concluded that the object belongs to WZ Sge type stars. The light…
AD Men was classified as a probable long-period dwarf nova based on its long-term variability. Recent spectroscopic data instead suggested a short-period system. With the here presented observations we aim at clarifying its nature.…
We have performed a Discrete Fourier Transform on 136 CCD B, V and R frames of the Z Cam-type dwarf nova V1101 Aql. Our analysis indicates as possible orbital period P_orb =3.46 hours, though we cannot exclude the alias at 4.00 hours. We…
The cyclic behaviour of (O-C) residuals of eclipse timings in the sdB+M eclipsing binary NSVS 14256825 was previously attributed to one or two Jovian-type circumbinary planets. We report 83 new eclipse timings that not only fill in the gaps…
Period analysis of CCD photometry of V1493 Aql (Nova Aql 1999 no. 1) performed during 12 nights through I and R filters a few weeks after maximum is presented. The PDM method for period analysis (Stellingwerf 1978) is used. The photometric…
To detect additional bodies in binary systems, we performed a potent approach of orbital period variation analysis. In this work, we present 90 new mid-eclipse times of a short-period eclipsing binary system. Observations were made using…
The old nova V728 Sco has been recently recovered via photometric and spectroscopic observations, 150 years after the nova eruption. The spectral properties pointed to a high-inclination system with a comparatively low mass-transfer rate.…
We report a photometric study of the WZ Sagittae-type dwarf nova PQ Andromedae. The light curve shows strong (0.05 mag full amplitude) signals with periods of 1263(1) and 634(1) s, and a likely double-humped signal with P=80.6(2) min. We…
We report CCD photometry of the dwarf nova BF Ara throughout fifteen consecutive nights in quiescence. Light curve in this interval is dominated by a large amplitude around 0.8 mag modulation consisting two periods. Higher amplitude signal…
We analyze 15 years of eclipse timings of the polar V808 Aur. The rapid ingress/egress of the white dwarf and bright accretion region provide timings as precise as a few tenths of a second for rapid cadence photometric data. We find that…
A period analysis of CCD unfiltered photometry of V4745 Sgr (Nova Sgr 2003 #1) performed during 23 nights in the years 2003 - 2005 is presented. The photometric data are modulated with a period of 0.20782 +- 0.00003 d ($4.98768 +- 0.00072…
New CCD photometric observations of BX Dra were obtained for 26 nights from 2009 April to 2010 June. The long-term photometric behaviors of the system are presented from detailed studies of the period and light variations, based on the…
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 have carried out an analysis of about 160 eclipse timings spanning over 30 years of the Hyades eclipsing binary V471 Tauri that shows a long-term quasi-sinusoidal modulation of its observed eclipse arrival times. The O-Cs have been…