Related papers: Precise Timing Analysis of Four Magnetic Cataclysm…

We update the ephemerides of 16 transiting exoplanets using our ground-based observations, new TESS data, and previously published observations including those of amateur astronomers. All these light curves were modeled by making use of a…

Many hot Jupiters may experience orbital decays, which are manifested as long-term transit timing variations. We have analyzed 7068 transits from the Transiting Exoplanet Survey Satellite (TESS) for a sample of 326 hot Jupiters. These new…

We analyze a 7.4 hr XMM-Newton light curve of the cataclysmic variable Swift J0503.7-2819, previously classified using optical periods as an intermediate polar (IP) with an orbital period of 0.0567 days. A photometric signal at 975 s,…

We report photometry of the helium-rich cataclysmic variable ES Ceti during 2001-2004. The star is roughly stable at V ~ 17.0 and has a light curve dominated by a single period of 620 s, which remains measurably constant over the 3 year…

We obtained time-series radial velocity spectroscopy of twenty cataclysmic variable stars, with the aim of determining orbital periods P_orb. All of the stars reported here prove to have P_orb > 3.5 h. For sixteen of the stars, these are…

Ultracompact accreting binary systems each consist of a stellar remnant accreting helium-enriched material from a compact donor star. Such binaries include two related sub-classes, AM CVn-type binaries and helium cataclysmic variables, in…

We present time-series VLT spectroscopy and NTT photometry of the cataclysmic variable SDSS J220553.98+115553.7, which contains a pulsating white dwarf. We determine a spectroscopic orbital period of 82.825 +/- 0.089 min from velocity…

We report on optical follow-up observations of an X-ray source initially detected by the Einstein Probe mission. Our investigations categorize the source as an intermediate polar, a class of magnetic cataclysmic variables, exhibiting an…

IGR J16493-4348 is an eclipsing supergiant high-mass X-ray binary (sgHMXB), where accretion onto the compact object occurs via the radially outflowing stellar wind of its early B-type companion. We present an analysis of the system's X-ray…

We present results from high speed photometry of a further thirteen faint cataclysmic variables. V356 Aql (Nova Aql 1936) shows flare-like outbursts with recurrence time scales ~ 3000 s, but no coherent periodicities. Aqr1 is an…

Five years of Rossi X-ray Timing Explorer (RXTE) observations of the Galactic black-hole candidates 1E 1740.7-2942 and GRS 1758-258 show a periodic modulation with amplitude 3-4% in each source at 12.73 +/- 0.05 dy and 18.45 +/- 0.10 dy,…

We present here results of an optical spectroscopic study of a new Cataclysmic Variable SDSS J001856.93+345444.3. We demonstrate that the most probable value of the orbital period of the system is Porb = 0.6051 \pm 0.022 days (=14.5226…

Context: We present a new study of the eclipsing cataclysmic variable CzeV404 Her (Porb = 0.098 d) that is located in the period gap. Aims: This report determines the origin of the object and the system parameters and probes the accretion…

Magnetic cataclysmic variables are close binaries which consist of a compact object - a white dwarf - and a red dwarf filling its Roche Lobe. Such systems are physical laboratories which enable study of the influence of magnetic fields on…

A recent development in the study of magnetic cataclysmic variable stars (mCVs) has been the identification of asynchronously spinning mCVs with orbital periods <2 h that have significantly higher white dwarf spin-to-orbital period ratios…

We aim to investigate variations in the arrival time of coherent stellar pulsations due to the light-travel time effect to test for the presence of sub-stellar companions. Those companions are the key to one possible formation scenario of…

We present follow-up photometric observations and time-series analysis of a nova-like, SW Sextans-type, cataclysmic variable (CV) candidate, LAMOST J204305.95+341340.6 (here after J2043+3413), with Gaia G-band magnitude of 15.30 and a…

We analysed the IGR J16465-4507 Burst Alert Teelescope survey data collected during the first 54 months of the Swift mission. The source is in a crowded field and it is revealed through an ad hoc imaging analysis at a significance level of…

Monitoring of pulse period variations in accreting binary pulsars is an important tool to study the interaction between the magnetosphere of the neutron star and the accretion disk. While the X-ray flux of the brightest X-ray pulsars have…

Among active galactic nuclei, blazars show extreme variability properties. We here investigate the case of the BL Lac object S4 0954+65 with data acquired in 2019-2020 by the Transiting Exoplanet Survey Satellite (TESS) and by the Whole…