Related papers: Orbital Period Increase in ES Ceti

Relativistic binary pulsars, such as B1534+12 and B1913+16 are characterized by having close orbits with a binary separation of ~ 3 R_\sun. The progenitor of such a system is a neutron star, helium star binary. The helium star, with a…

Kepler-16 is an eccentric low-mass eclipsing binary with a circumbinary transiting planet. Here we investigate the angular momentum of the primary star, based on Kepler photometry and Keck spectroscopy. The primary star's rotation period is…

New multiband CCD photometry is presented for the eclipsing binary GW Gem; the $RI$ light curves are the first ever compiled. Four new minimum timings have been determined. Our analysis of eclipse timings observed during the past 79 years…

The Cepheid AW Per is a component in a multiple system with a long period orbit. The radial velocities of Griffin (2016) cover the 38 year orbit well. An extensive program of interferometry with the CHARA array is reported here, from which…

We present a ground based photometry of the low-temperature contact binary BB Peg. We collected all times of mid-eclipses available in literature and combined them with those obtained in this study. Analyses of the data indicate a period…

We searched for circumbinary planets orbiting NY Vir in historical eclipse times including our long-term CCD data. Sixty-eight times of minimum light with accuracies better than 10 s were used for the ephemeris computations. The best fit to…

The latest Gaia Focused Product Release (FPR) provided variability information for $\sim$1000 long-period red giant binaries, the largest sample to date of this binary type having both photometric and spectroscopic time series observations.…

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…

A radial-velocity monitoring of the Carbon-Enhanced Metal-Poor (CEMP) star HE 0017+0055 over 8 years with the Nordic Optical Telescope and Mercator telescopes reveals variability with a period of 384 d and amplitude of 540$\pm27$ m…

LSI +61 303 is an exotic binary system consisting of a ~10 Msun B star and a compact object which is probably a neutron star. The system is associated with the interesting radio source GT0236+610 that exhibits bright radio outbursts with a…

In the absence of detectable pulsations in the eclipsing High Mass X-ray binary 4U 1700-37, the orbital period decay is necessarily determined from the eclipse timing measurements. We have used the earlier reported mid-eclipse time…

RX J1914.4+2456 is a candidate double-degenerate binary (AM CVn) with a putative 569 s orbital period. If this identification is correct, then it has one of the shortest binary orbital periods known, and gravitational radiation should drive…

We report the discovery of ZTF J0127+5258, a compact mass-transferring binary with an orbital period of 13.7 minutes. The system contains a white dwarf accretor, which likely originated as a post-common envelope carbon-oxygen (CO) white…

We report time-series photometry of the quiescent optical counterpart of the EUV transient RE J1255+266. The star appears as a DA white dwarf with bright emission lines and a complex spectrum of periodic signals in its light curve. A signal…

We present optical spectroscopy of MWC 656 and MWC 148, the proposed optical counterparts of the gamma-ray sources AGL J2241+4454 and HESS J0632+0 57, respectively. The main parameters of the Halpha emission line (EW, FWHM and centroid…

In this paper we investigate the possibility of measuring the general relativistic gravitoelectric contribution P^(GE) to the orbital period P of the transiting exoplanet HD 209458b 'Osiris'. It turns out that the predicted magnitude of…

A nonlinear nature of the binary ephemeris of Cygnus X-3 indicates either a change in the orbital period or an apsidal motion of the orbit. We have made extended observations of Cygnus X-3 with the Pointed Proportional Counters (PPCs) of…

As a result of various studies, it has been determined that several post-common envelope eclipsing binaries have variations in their orbital periods. These variations are thought to be caused by the existence of additional bodies in the…

LS I + 61$^\circ$303 is a high-mass X-ray binary system comprising a massive Be star and a rapidly rotating neutron star. Its spectral energy distribution across multi-wavelengths categorizes it as a $\gamma$-ray binary system. In our…

Time-series, multi-color photometry and high-resolution spectra of the short period eclipsing binary V Tri were obtained by observations. The completely covered light and radial velocity curves of the binary system are presented. All times…