Related papers: Identification of SRGt 062340.2-265715 as a bright…

We report on very-high-energy ($>$100 GeV) gamma-ray observations of Swift J164449.3+573451, an unusual transient object first detected by the {\it Swift} Observatory and later detected by multiple radio, optical and X-ray observatories. A…

We present a sample of cataclysmic variables (CVs) identified among the X-ray sources from the 400 square degree X-ray survey based on ROSAT pointing data (400d). The procedure of the CV selection among the X-ray sources using additional…

W2 (CXOGlb J002415.8-720436) is a cataclysmic variable (CV) in the Galactic globular cluster 47 Tucanae. Its modulation was discovered within the CATS@BAR project. The source shows all the properties of magnetic CVs, but whether it is a…

We present the results of our study of ASASSN-14dx, a previously known but poorly characterised cataclysmic variable (CV). The source was observed as part of an ongoing high-time-resolution photometric survey of CVs, which revealed that, in…

The ROSAT source RX J1039.7-0507, known from its optical spectrum to be a Cataclysmic Variable star, is shown from high speed photometry to have an orbital period of 1.574 h. The system has a nearly sinusoidal photometric modulation with a…

We report on a quasi-periodic variation at $\sim1$ Hz during a fast X-ray outburst of a high-mass X-ray binary MAXI J0709$-$159 / LY CMa observed by the Neutron-star interior composition explorer (NICER). The new X-ray transient MAXI…

HESS J0632+057 is the only gamma-ray binary known so far whose position in the sky allows observations with ground-based observatories both in the northern and southern hemispheres. Here we report on long-term observations of HESS J0632+057…

We present the results of the optical identification, classification, as well as analysis of photometric and spectral observations of the X-ray transient SRGe2149+6736 detected by the eROSITA telescope during SRG all-sky X-ray survey.…

HESS J0632+057 has been recently identified as a new gamma-ray binary system. The source, located in the Monoceros region and associated with the massive Be star MWC 148, shows variability from radio to very high energy (VHE) gamma-rays,…

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…

The Transient Gamma Ray Spectrometer (TGRS) on board the WIND spacecraft has spent most of the interval 1995-1997 in a high-altitude orbit where gamma-ray backgrounds are low. Its high-resolution Ge spectrometer is thus able to detect weak…

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…

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…

AM CVn-type systems are ultracompact, helium-accreting binary systems which are evolutionarily linked to the progenitors of thermonuclear supernovae and are expected to be strong Galactic sources of gravitational waves detectable to…

We present photometry and spectroscopy of the suspected cataclysmic variable (CV) Lanning 386. We confirm that it is a CV, and observe deep eclipses, from which we determine the orbital period Porb to be 0.1640517 +- 0.0000001 d (= 3.94 h).…

The good energy resolution (3--4 keV FWHM) of the Transient Gamma Ray Spectrometer (TGRS) on board the WIND spacecraft makes it sensitive to Doppler-shifted outbursts of 511 keV electron-positron annihilation radiation, the reason being…

Using data from eROSITA, the soft X-ray instrument aboard Spectrum-Roentgen-Gamma (SRG), we report the discovery of two new hard transients, eRASSU J050810.4-660653 and eRASSt J044811.1-691318, in the Large Magellanic Cloud. We also report…

We report the discovery of a bright (V ~ 15), eclipsing, two-pole accreting magnetic cataclysmic variable (CV), a polar, as counterpart of the eROSITA and Gaia transients eRASSt 192932.9-560346 and Gaia21bxo. Frequent large amplitude…

Motivated by the existence of binary systems where a stellar-mass black hole is bound to a normal star, we selected four red giants with large radial velocity (RV) variation from the survey of SIM grid stars and monitored their RVs for…

We present the TESS observations of CRTS J110014.7+131552, SDSS J093537.46+161950.8, and [PK2008] HalphaJ130559. Among them, a superoutburst is observed in CRTS J110014.7+131552 which is associated with the precursor outburst, where…