Related papers: Apsidal motion in massive close binary systems. I.…

We carried out a spectroscopic and photometric analysis of the binary V4089 Sgr with the aim to obtain absolute masses and radii of the components and to compare these parameters with stellar evolution theoretical models. We took…

We present the apsidal motion and light-curve analyses of 21 eccentric eclipsing binaries located in the Small Magellanic Cloud. Most of these systems have never been studied before, hence their orbital and physical properties as well as…

The bright southern binary star beta Centauri (HR 5267) has been observed with the Sydney University Stellar Interferometer (SUSI) and spectroscopically with the ESO CAT and Swiss Euler telescopes at La Silla. The interferometric…

We present results from Speckle inteferometric observations of fifteen visual binaries and one double-line spectroscopic binary, carried out with the HRCam Speckle camera of the SOAR 4.1 m telescope. These systems were observed as a part of…

We report about HD 213258, an Ap star that we recently identified as presenting a unique combination of rare, remarkable properties. Our study of this star is based on ESPaDOnS Stokes I and V data obtained at 7 epochs spanning a time…

We have used the Palomar Testbed Interferometer to perform very high precision differential astrometry on the 0.25 arcsecond separation binary star HD 171779. In 70 minutes of observation we achieve a measurement uncertainty of…

We determine the absolute dimensions of the eclipsing binary V578 Mon, a detached system of two early B-type stars (B0V + B1V, P$=$2.40848 d) in the star-forming region NGC 2244 of the Rosette Nebula. From the light curve analysis of 40 yr…

We have used spectra taken between 1992 and 1997 to derive the spectroscopic orbit of the eclipsing double-lined spectroscopic binary HD 197770. This binary has a period of 99.69 +/- 0.02 days and K amplitudes of 31.2 +/- 0.8 and 47.1 +/-…

Radial-velocity measurements and sine-curve fits to the orbital velocity variations are presented for the eighth set of ten close binary systems: AB And, V402 Aur, V445 Cep, V2082 Cyg, BX Dra, V918 Her, V502 Oph, V1363 Ori, KP Peg, V335…

In recent years the idea, first formulated many decades ago, that the Be phenomenon could be causally related to the duplicity of Be stars, has been repeatedly reconsidered from various perspectives. It is important, therefore, to have…

We present a preliminary spectroscopic analysis of the binary system V577Oph, observed during the summer of 2007 on the 2.6m NOT telescope on La Palma. We have obtained time series spectroscopic observations, which show clear binary motion…

Aims. We present the results of our detailed spectroscopic and photometric analysis of two previously unknown < 1 M{_\sun} detached eclipsing binaries: ASAS J045304-0700.4 and ASAS J082552-1622.8. Methods. With the HIgh Resolution Echelle…

Analysis of spectra of the quasar 3C 390.3 covering a period of over 20 yr shows that the blueshifted peak of H beta has been changing its radial velocity at an almost constant rate during this time. The radial velocity has increased by…

We report the discovery of the wide L1.5+L4.5 binary 2MASS J15200224-4422419AB, identified during spectroscopic followup of high proper motion sources selected from the Two Micron All Sky Survey. This source was independently identified by…

Wide binaries are tracers of the gravity field of the Galaxy, but their study requires some caution. A large list of common proper motion stars selected from the AGK3 were monitored with the CORAVEL spectrovelocimeter, in order to prepare a…

We present the analysis of 29.77 days of K2 space photometry of the well-detached massive 4.6 d O+B binary HD 165246 (V=7.8) obtained during Campaign 9b. This analysis reveals intrinsic variability in the residual lightcurve after…

We present intermediate resolution spectroscopy of the optical counterpart to the black hole X-ray transient MAXI J1820+070 (=ASASSN-18ey) obtained with the OSIRIS spectrograph on the 10.4-m Gran Telescopio Canarias. The observations were…

Radial velocity data are presented for 10 W UMa-type systems: GZ And, V417 Aql, LS Del, EF Dra, V829 Her, FG Hya, AP Leo, UV Lyn, BB Peg, AQ Psc, together with preliminary, circular-orbit determinations of spectroscopic elements, with the…

We present a detailed study of KIC 2306740, an eccentric double-lined eclipsing binary system. Kepler satellite data were combined with spectroscopic data obtained with the 4.2 m William Herschel Telescope (WHT). This allowed us to…

We estimated the contribution of binary systems to the velocity dispersion inside OB-associations derived from Gaia DR2 proper motions. The maximum contribution to the velocity dispersion is given by the systems with the period of…