Related papers: The Z Camelopardalis-type star AY Piscium: stellar…
Balmer and Paschen continuum emission as well as Balmer series lines of P Cygni-type profile from H_gamma through H_23 are revealed in the violet spectra of BM Gem, a carbon star associated with an oxygen-rich circumstellar shell (`silicate…
We present a long-term optical and X-ray photometric study of AN UMa, one of the prototypical polar-type cataclysmic variables, tracing more than 34 years of its accretion history. Observations from both ground-based and space-based…
We present results from ASCA observations of the binary CI Cam both in quiescence and in outburst in order to identify its central accreting object. The quiescence spectrum of CI Cam consists of soft and hard components which are separated…
We show that the disc instability model can reproduce all the observed properties of Z Cam stars if the energy equation includes heating of the outer disc by the mass-transfer stream impact and by tidal torques and if the mass-transfer rate…
PY Per has been known as a Z Cam star. Using VSOLJ, VSNET, AAVSO, ASAS-SN and ZTF observations, I found that this object experienced faint states and classified it to be a Z Cam + VY Scl star. Furthermore, the object changed the outburst…
In this study, we conducted a comprehensive analysis of the SX Phoenicis (SX Phe) type star CY Aquarii (CY Aqr). Our investigation included a detailed $O-C$ analysis based on a 90-year observational dataset, augmented by 1,367 newly…
RZ Psc is an isolated high-latitude post-T Tauri star that demonstrates a UX Ori-type photometric activity. The star shows very weak spectroscopic signatures of accretion, but at the same time possesses the unusual footprints of the wind in…
We present the complete set of thirty four ASCA observations of non-magnetic cataclysmic variables. Timing analysis reveals large X-ray flux variations in dwarf novae in outburst (Z Cam, SS Cyg and SU UMa) and orbital modulation in high…
The Z Cam stars IW And and V513 Cas are unusual in having outbursts following their standstills in contrast to the usual Z Cam behavior of quiescence following standstills. In order to gain further understanding of these little-studied…
The Be star $\pi$ Aquarii shows peculiar $\gamma$ Cas-type X-ray emission, likely caused by its outer disk interacting with a low-mass companion, probably a white dwarf. We study the long-term variability of its optical spectra to derive…
We report a 20-year campaign to track the 1.8 hour photometric wave in the recurrent nova T Pyxidis, using the global telescope network of the Center for Backyard Astrophysics. During 1996-2011, that wave was highly stable in amplitude and…
Using high resolution UVES spectra of the eclipsing Post Common Envelope Binary QS Vir we detect material along the line of sight to the white dwarf at orbital phase $\phi=0.16$. We ascribe this to a stellar prominence originating from the…
Based on high-resolution optical spectroscopy in the blue and the near infra-red spectral range, we derived velocity images (Doppler tomograms) of the mass-donating secondary star and the accretion stream of the long-period eclipsing polar…
T Pyx is a luminous recurrent nova that accretes at a much higher rate than is expected for its photometrically determined orbital period of about 1.8 hours. We here provide the first spectroscopic confirmation of the orbital period, P…
We present Hubble Space Telescope ultraviolet spectroscopy of the recurrent nova T Pyxidis obtained more than 5 years after its 2011 outburst indicating that the system might not have yet reached its deep quiescent state. The ultraviolet…
The spectra of disc-dominated cataclysmic variables (CVs) often deviate from the spectra of accretion disc models; in particular, the Balmer jump and absorption lines are found to be shallower in the observations than in the models. We…
We present high-speed, three-colour photometry of the eclipsing dwarf nova KIS J192748.53+444724.5 which is located in the Kepler field. Our data reveal sharp features corresponding to the eclipses of the accreting white dwarf followed by…
We present our analysis of new and archived observations of two candidate magnetic cataclysmic variables, namely 1RXS J174320.1-042953 and YY Sex. 1RXS J174320.1-042953 was observed in two distinctive high and low states where a phase shift…
Y Cam is classified as one of the oscillating Eclipsing Algol (oEA) systems, which feature a $\delta$ Scuti-type pulsating component alongside mass transfer phenomena. oEA systems are invaluable for probing the evolutionary processes and…
Dwarf novae are semi-detached binaries, where a white dwarf accretes material from a cool main-sequence companion via an accretion disk, and are known for their intermittent outbursts, making them key systems for studying accretion physics.…