Related papers: Dynamical Masses for the Hyades Binary System vB 1…

New spectroscopic observations of the LBV/WR multiple system HD5980 in the Small Magellanic Cloud are used to address the question of the masses and evolutionary status of the two very luminous stars in the 19.3d eclipsing binary system.…

We confirmed the binary nature of the Be star 7~Vul, derived a~more accurate spectroscopic orbit with an orbital period of (69.4212+/-0.0034) d, and improved the knowledge of the basic physical elements of the system. Analyzing available…

We present the visual orbits of four spectroscopic binary stars, HD 61859, HD 89822, HD 109510, and HD 191692, using long baseline interferometry with the CHARA Array. We also obtained new radial velocities from echelle spectra using the…

Individual components of well-detached binary systems are assumed to be two single-like stars with a common origin, i.e. they share the same chemical composition and same age. Therefore, one expects to fit the observed parameters of both…

Using the censored catalog of 103,169 resolved Gaia DR3 binary stars with accurate astrometric data for each component, a new observable, object-specific parameter is computed for each pair: the projected orbital momentum. This parameter is…

In a search for common proper motion companions using the VISTA Hemisphere Survey and 2MASS catalogs we have identified a very red (J-Ks=2.47 mag) late-L dwarf companion of a previously unrecognized M dwarf VHS J125601.92-125723.9, located…

Astrophysical models of binary-black hole mergers in the Universe require a significant fraction of stellar-mass black holes (BHs) to receive negligible natal kicks to explain the gravitational wave detections. This implies that BHs should…

We use photometric and spectroscopic observations of the detached eclipsing binary V209 omega Cen to derive the masses, radii, and luminosities of the component stars. The system exhibits total eclipses and, based on the measured systemic…

Context. The precise determinations of stellar mass at $\sim$1% provide important constraints on stellar evolution models. Accurate parallax measurements can also serve as independent benchmarks for the next Gaia data release. Aims. We aim…

We aim to improve the orbital elements and determine the individual masses of the components in the triple system TWA 5. Five new relative astrometric positions in the H band were recorded with the adaptive optics system at the Very Large…

As part of a program to determine dynamical masses of Cepheids, we have imaged the nearest and brightest Cepheid, Polaris, with the Hubble Space Telescope Wide Field Planetary Camera 2 and Wide Field Camera 3. Observations were obtained at…

We present a comprehensive photometric analysis of a young open cluster NGC 1960 (M36) along with the long-term variability study of this cluster. Based on the kinematic data of Gaia DR2, the membership probabilities of 3871 stars are…

We have determined the dynamical mass of the most luminous stellar cluster known to date, i.e. object W3 in the merger remnant galaxy NGC 7252. The dynamical mass is estimated from the velocity dispersion measured with the high-resolution…

Astrometric observations of resolved binaries provide estimates of orbital periods and will eventually lead to measurement of dynamical masses. Only a few very low mass star and brown dwarf masses have been measured to date, and the…

We present an analysis of nine bright spectroscopic binaries (HD 1585, HD 6613, HD 12390, HD 39923, HD 55201, HD 147430, HD 195543, HD 202699, HD 221643), which have orbital periods of P > 500 days. These well-separated binaries are the…

Using high-contrast imaging with the SPHERE instrument at the VLT, we report the first images of a cold brown dwarf companion to the exoplanet host star HD4113A. The brown dwarf HD4113C is part of a complex dynamical system consisting of a…

We present the results of time-resolved spectroscopy of 13 O-type stars in the Cas OB6 stellar association. We conducted a survey for radial velocity variability in search of binary systems, which are expected to be plentiful in young OB…

The 3D velocities of M31 and M33 are important for understanding the evolution and cosmological context of the Local Group. Their most massive stars are detected by Gaia, and we use Data Release 2 (DR2) to determine the galaxy proper…

We present the stellar parameters of the individual components of the two old close binary systems HIP\,14075 and HIP\,14230 using synthetic photometric analysis. These parameters are accurately calculated based on the best match between…

We present a detailed analysis of the detached eclipsing binary system HO Telescopii, which contains two A-type stars in a circular orbit of period 1.613 d. We use light curves from the Transiting Exoplanet Survey Satellite (TESS), which…