Related papers: Gaia19bxc: possible polar below the period minimum

We report on the discovery of the shortest period binary comprising a hot subdwarf star (CD-30 11223, GALEX J1411-3053) and a massive unseen companion. Photometric data from the All Sky Automated Survey show ellipsoidal variations of the…

In course of the search for the optical identifications associated with ROSAT X-ray sources we have found a highly variable object with the very unusual long-term behavior, color indices and high X-ray-to-optical flux ratio. We report the…

We have measured the orbital parameters of seven close binaries, including six new objects, in a radial velocity survey of 38 objects comprising a hot subdwarf star with orbital periods ranging from ~0.17 to 3 d. One new system, GALEX…

We present the results of a photometric and spectroscopic analysis of the Galactic Bulge Survey X-ray source CXOGBS J174954.5-294335 (hereafter, referred to as CX19). CX19 is a long period, eclipsing intermediate polar type cataclysmic…

A new magnetic cataclysmic variable is identified as the counterpart of the X-ray source RX J0719.2+6557. The emission lines show radial velocity variations with a period of 98.2 min. This coincides with the period of deep eclipses (up to 4…

We present the discovery and CCD observations of the first eclipsing binary with a Type II Cepheid component in our Galaxy. The pulsation and orbital periods are found to be 4.1523 and 51.38 days, respectively, i.e. this variable is a…

Secondary stars in cataclysmic variables (CVs) follow a well defined period-density relation. Thus, canonical donor stars in CVs are generally low-mass stars of spectral type M. However, several CVs have been observed containing secondary…

White dwarfs are well studied objects. The relative simplicity of their physics allows to obtain very detailed models which can be ultimately compared with their observed properties. Among white dwarfs there is a specific class of stars,…

Spectra of 38 candidate or known cataclysmic variables are presented. Most are candidate dwarf novae or systems containing possible highly magnetic white dwarfs, while a few (KR Aur, LS Peg, V380 Oph and V694 Mon) are previously known…

We have performed time resolved photometry on the dwarf nova CG Dra and have established for the first time that it is an eclipsing system. By measuring the times of the eclipses, we determined the orbital period as 0.18864(4) d, or 4h 31m…

The many unusual properties of the enigmatic AT2018cow suggested that at least some subset of the empirical class of fast blue optical transients (FBOTs) represents a genuinely new astrophysical phenomenon. Unfortunately, the intrinsic…

Context. The origin, evolution, and ultimate fate of magnetic cataclysmic variables are poorly understood. It is largely the nature of the magnetic fields in these systems that leads to this poor understanding. Fundamental properties, such…

The high-frequency radio sky is bursting with synchrotron transients from massive stellar explosions and accretion events, but the low-frequency radio sky has so far been quiet beyond the Galactic pulsar population and the long-term…

This is the second paper of a series presenting our search for magnetic Cataclysmic Variables (mCVs) among candidates selected mostly from the Catalina Real-Time Transient Survey (CRTS). We present the identification spectra, obtained at…

Since July 2014, the Gaia mission has been engaged in a high-spatial-resolution, time-resolved, precise, accurate astrometric, and photometric survey of the entire sky. Aims: We present the Gaia Science Alerts project, which has been in…

The discovery of an exomoon would provide deep insights into planet formation and the habitability of planetary systems, with transiting examples being particularly sought after. Of the hundreds of Kepler planets now discovered, the…

White dwarfs (WDs) are the most abundant compact objects, and recent surveys have suggested that over a third of WDs in accreting binaries host a strong (B $\gtrsim$ 1 MG) magnetic field. However, the origin and evolution of WD magnetism…

In this study, we report a discovery from XMM-Newton, which involves the identification and subsequent examination of a newly discovered polar-type cataclysmic variable named XMM J152737.4-205305.9. The discovery was made by matching the…

We present optical photometry of the cataclysmic variable LAMOST J024048.51+195226.9 taken with the high-speed, five-band CCD camera HiPERCAM on the 10.4 m Gran Telescopio Canarias (GTC). We detect pulsations originating from the spin of…

We present follow-up photometry and spectroscopy of ZTF J0328$-$1219 strengthening its status as a white dwarf exhibiting transiting planetary debris. Using TESS and Zwicky Transient Facility photometry, along with follow-up high speed…