Related papers: HS Hya about to turn off its eclipses
Recent observations have shown that at least some close-in exoplanets maintain eccentric orbits despite tidal circularization timescales that are typically shorter than stellar ages. We explore gravitational interactions with a distant…
Differential astrometry measurements from the Palomar High-precision Astrometric Search for Exoplanet Systems have been combined with lower precision single-aperture measurements covering a much longer timespan (from eyepiece measurements,…
A new determination of the orbit of the Hyades double-lined spectroscopic binary HD 27149 is presented. The well-defined orbit provides the spectroscopic basis for an extremely accurate orbital parallax for the system -- in particular, the…
$\xi$ Tau is one of the most compact multiple stellar systems, which is sufficiently close (67 pc) to be constrained by all kinds of observations. To better constrain its current configuration, we utilized new observational data: (i)…
The lightcurve of CoRoT-2 shows substantial rotational modulation and deformations of the planet's transit profiles caused by starspots. We consistently model the entire lightcurve, including both rotational modulation and transits,…
The systems V819 Her, V2388 Oph, and V1031 Ori are triples comprised of an eclipsing binary orbiting with a distant visual component on a longer orbit. A detailed analysis of these interesting systems, combining the two observational…
The Mira variable R Hydrae is well known for its declining period, which Wood & Zarro (1981) attributed to a possible recent thermal pulse. Here we investigate the long-term period evolution, covering 340 years, going back to its discovery…
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…
A dense series of long and high time resolution light curves of the old nova V603 Aql, covering 22 nights (19 of which are consecutive), are analyzed in order to identify and characterize variations on the time scale of hours and days. The…
The new B and V photoelectric observations of the beta Lyrae eclipsing binary DO Cas were obtained on 6 nights form December 2000 to January 2001. The observations were made at the Biruni Observatory, Shiraz, Iran and the light curves are…
The Kepler object KIC 12557548 shows irregular eclipsing behaviour with a constant 15.685 hr period, but strongly varying transit depth. In this paper we fit individual eclipses, in addition to fitting binned light curves, to learn more…
We present time-resolved V-photometry of the old nova RR Pic. Apart from the hump-like variability, the light curves show the strong flickering and random variation typical for RR Pic. We do not find any convincing evidence for the…
The magnetic cataclysmic variable HU Aquarii displayed pronounced quasi-periodic modulations of its eclipse timing. These were interpreted in terms of the light-travel time (LTT) effect caused by a circumbinary planet or planetary system.…
Photometric observations in V and I bands of six eclipsing binaries at the lower limit of the orbital periods of W UMa stars are presented. Three of them are newly discovered eclipsing systems. The light curve solutions revealed that all…
We report on a timing of the eclipse arrival times of the low mass X-ray binary and X-ray pulsar 2A 1822-371 performed using all available observations of the Proportional Counter Array on board the Rossi X-ray Timing Explorer, XMM-Newton…
We present photometry of HD 189733 during eight transits of its close-in giant planet, and out-of-transit photometry spanning two years. Using the transit photometry, we determine the stellar and planetary radii and the photometric…
The observational picture of the enigmatic O-type spectrum variable HD191612 has been sharpened substantially. A symmetrical, low-amplitude light curve with a period near 540 d has recently been reported from Hipparcos photometry. This…
Results are presented of a five-year project to study the orbital periods of eighteen deeply eclipsing novalike cataclysmic variables, collectively known as SW Sextantis stars, by combining new measurements of eclipse times with published…
New CCD photometry is presented for the hot overcontact binary DK Cyg, together with reasonable explanations for the light and period variations. Historical light and velocity curves from 1962 to 2012 were simultaneously analyzed with the…
Hierarchical triple systems comprise a close binary and a more distant component. They are important for testing theories of star formation and of stellar evolution in the presence of nearby companions. We obtained 218 days of Kepler…