Related papers: Period Analysis of Eclipsing Cataclysmic Variable …
We present time-resolved optical spectroscopy and photometry of four relatively bright (V~14.0-15.5) long-period cataclysmic variables (CVs) discovered in the Hamburg Quasar Survey: HS0139+0559, HS0229+8016, HS0506+7725 and HS0642+5049.…
VY Scl binaries are a sub-class of cataclysmic variable (CV) which show extended low states, but do not show outbursts which are seen in other classes of CV. To better determine how often these systems spend in low states and to resolve the…
A third body in an eclipsing binary system causes regular periodic changes in the observed (O) minus the computed (C) eclipse epochs. Fourth bodies are rarely detected from the O-C data. We apply the new Discrete Chi-square method (DCM) to…
AM CVn systems are a rare (about a dozen previously known) class of cataclysmic variables, arguably encompassing the shortest orbital periods (down to about 10 minutes) of any known binaries. Both binary components are thought to be…
We have compiled the first all-sky mid-infrared variable-star catalog based on Wide-field Infrared Survey Explorer (WISE) five-year survey data. Requiring more than 100 detections for a given object, 50,282 carefully and robustly selected…
The COROT space mission will monitor several target fields for up to 150 days to perform asteroseismology and to search for extrasolar planets by photometric transits. Variable stars in the target fields are important objects for additional…
We give an identification summary and results of polarimetric, photometric and spectroscopic follow-up observations of new, X-ray bright cataclysmic variables. These were identified as optical counterparts of high galactic latitude sources…
Transiting exoplanets in multi-planet systems exhibit non-Keplerian orbits as a result of the gravitational influence from companions which can cause the times and durations of transits to vary. The amplitude and periodicity of the transit…
We present the results of a photometric survey for variable stars in the central region of the nearby globular cluster NGC 6397.Time series photometry was obtained for 30 variable objects. The sample includes 12 new objects, of which 6 show…
We review the recent knowledge base pertaining to causes for mass accretion variations (high/low states) in highly magnetic cataclysmic variables (i.e. polars). We then examine what theory has to say about the properties of the secondary…
The theoretical and observed populations of pre-cataclysmic variables (pre-CVs) are dominated by systems with low-mass white dwarfs (WDs), while the WD masses in CVs are typically high. In addition, the space density of CVs is found to be…
The discovery and characterization of Algol eclipsing binaries (EAs) provide an opportunity to contribute for a better picture of the structure and evolution of low-mass stars. However, the cadence of most current photometric surveys…
We report a study of the eclipse timing variation (ETV) of short period ($P_1\le 6^d$) eclipsing binaries (EB) monitored during the photometric survey OGLE-IV. From the 425\,193 EBs we selected approximately 80\,000 binaries that we found…
Transit timing variation (TTV) is a useful tool for studying the orbital properties of transiting objects. However, few TTV studies have been done on transiting brown dwarfs (BDs) around solar-type stars. Here we study the long-term TTV of…
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…
A short period eclipsing binary star CV Boo is tested for the possible existence of additional bodies in the system with a help of the light equation method. We use data on the moments of minima from the literature as well as from our…
We present a systematic search for periodic X-ray sources in 10 Galactic globular clusters (GCs) utilizing deep archival Chandra observations. By applying the Gregory-Loredo algorithm, we detect 28 periodic signals among 27 independent…
The orbital periods of most eclipsing cataclysmic binaries are not undergoing linear secular decreases of order a few parts per billion as expected from simple theory. Instead, they show several parts per million increases and decreases on…
HW Vir is a short-period binary that presents eclipse timing variations. Circumbinary planets have been proposed as a possible explanation, although the properties of the planets differ in each new study. Our aim is to perform robust model…
This work presents the first high-precision variability survey in the field of the intermediate-age, metal--rich open cluster NGC 6253. Clusters of this type are benchmarks for stellar evolution models. Continuous photometric monitoring of…