Related papers: A celestial matryoshka: Dynamical and spectroscopi…

We subjected 106 new high-resolution spectra of the double-lined spectroscopic close binary epsilon Lupi, obtained in a time-span of 17 days from two different observatories, to a detailed study of orbital and intrinsic variations. We…

We present higher-order multiplicity results for 60 solar-type spectroscopic binaries based on 0.75 micron imaging data taken by the Robotic Adaptive Optics system (Robo-AO) at the Kitt Peak 2.1m telescope. Our contrast curves show…

We report the discovery and orbital solutions for two new OB binaries in the Cygnus OB2 Association, MT311 (B2V+B3V) and MT605 (B0.5V+B2.5:V). We also identify the system MT429 as a probable triple system consisting of a tight eclipsing…

We present the first resolved images of the eclipsing binary Beta Lyrae, obtained with the CHARA Array interferometer and the MIRC combiner in the H band. The images clearly show the mass donor and the thick disk surrounding the mass gainer…

Aims: Detect tertiary components of close binaries from spectroscopy and light curve modelling; investigate light-travel time effect and the possibility of magnetic activity cycles; measure mass-ratios for unstudied systems and derive…

Close binary interactions may play a critical role in the formation of the rapidly rotating Be stars. Mass transfer can result in a mass gainer star spun up by the accretion of mass and angular momentum, while the mass donor is stripped of…

Aims. We look for common proper motion companions to stars of the nearby young beta Pictoris moving group. Methods. First, we compiled a list of 185 beta Pictoris members and candidate members from 35 representative works. Next, we used the…

Summed many years of work at Pulkovo, the orbits of 67 wide pairs of visual double and multiple stars (included in 64 systems) which were obtained by the Apparent Motion Parameters (AMP) method are presented. This short arc determination…

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 provide a complete characterization of the astrophysical properties of the $\sigma$ Ori Aa,Ab,B hierarchical triple system, and an improved set of orbital parameters for the highly eccentric $\sigma$ Ori Aa,Ab spectroscopic binary. We…

(Abridged) We present spectroscopic and photometric observations of the eclipsing system V1061 Cyg (P = 2.35 days). We show that it is a hierarchical triple in which the third star is visible in the spectra. We combine the radial velocities…

In this research, five eclipsing binary stars were studied: AB Cas, AF Gem, AR Boo, BF Vir and CL Aur. The large sets of moments of minima were used: from the international BRNO database and amateur observations from the database AAVSO.…

delta Velorum is a nearby (24pc) triple stellar system, containing a close, eclipsing binary (Aa, Ab) discovered in 2000. Multiple systems provide an opportunity to determine the set of fundamental parameters (mass, luminosity, size and…

We report on the results of a six-month photometric study of the main-belt binary C-type asteroid 121 Hermione, performed during its 2007 opposition. We took advantage of the rare observational opportunity afforded by one of the annual…

Mass ratios of widely separated, long-period, resolved binary stars can be directly estimated from the available data in major space astrometry catalogs, such as the ESA's Hipparcos and Gaia mission results. The method is based on the…

In 1981, Beta Pictoris showed strong and rapid photometric variations possibly due to a transiting giant planet. Later, a planetary mass companion to the star, Beta Pic b, was identified using imagery. Observations at different epochs (2003…

Although delta Scorpii is a bright and well-studied star, the details of its multiplicity have remained unclear. Here we present the first diffraction-limited image of this 0.12 arcsec binary star, made using optical interferometry, and…

Using the absolute astrometric positions and proper motions for common stars in the Hipparcos and Gaia catalogs separated by 24.75 years in the mean epoch, we compute mass ratios for long-period, resolved binary systems without any…

We aim to measure very precise and accurate model-independent masses and distances of detached binary stars. Precise masses at the $< 1$% level are necessary to test and calibrate stellar interior and evolution models, while precise and…

The predicted orbital-period distribution of the subdwarf-B (sdB) population is bi-modal with a peak at short (< 10 days) and long (> 500 days) periods. Observationally, many short-period sdB systems are known, but only few wide sdB…