Related papers: Binary Masses as a Test for Pre-Main-Sequence Mode…
The recent Gaia third data release (DR3) has brought some new exciting data about stellar binaries. It provides new opportunities to fully characterize more stellar systems and contribute to enforce our global knowledge of stars behaviour.…
The statistics of catalogued quadruple stars consisting of two binaries (hierarchy 2+2) is studied in comparison with triple stars, with respective sample sizes of 81 and 724. Seven representative quadruple systems are discussed in greater…
We compile observations of early-type binaries identified via spectroscopy, eclipses, long-baseline interferometry, adaptive optics, common proper motion, etc. Each observational technique is sensitive to companions across a narrow…
Aims. Having established the binary status of nineteen O-type stars located in four Cygnus OB associations, we now determine their fundamental parameters to constrain their properties and their evolutionary status. We also investigate their…
Multiwavelength opportunities have provided important new insights into the properties of binary/multiple 5 Msun stars. The combination of cool evolved primaries and hot secondaries in Cepheids (geriatric B stars) has yielded detailed…
We use a homogeneous catalog of 42,000 main-sequence wide binaries identified by Gaia to measure the mass ratio distribution, p(q), of binaries with primary masses $0.1<M_1/M_{\odot}<2.5$, mass ratios $0.1 \lesssim q<1$, and separations…
To address the statistics of binary stars in the 8-Myr old Upper Scorpius star formation region, we conducted speckle-interferometric survey of 614 association members more massive than 0.4 Msun (spectral types earlier than M3V) based on…
M35 is a young open cluster and home to an extensive binary population. Using Gaia DR3, Pan-STARRS, and 2MASS photometry with the Bayesian statistical software, BASE-9, we derive precise cluster parameters, identify single and binary…
We report about an ongoing photometric and spectroscopic monitoring survey of about 250 O- and 540 B-type stars in the southern Milky Way with the aim to determine the fraction of close binary systems as a function of mass and to determine…
Evolutionary tracks are of key importance for the understanding of star formation. Unfortunately, tracks published by various groups differ so that it is fundamental to have observational tests. In order to do this, we intend to measure the…
DQ Tau is a young low-mass spectroscopic binary, consisting of two almost equal-mass stars on a 15.8 day period surrounded by a circumbinary disk. We analyzed DQ Tau's light curves obtained by Kepler K2, the Spitzer Space Telescope, and…
Context: The calibration of binary systems with accurately known masses and/or radii provides powerful tools to test stellar structure and evolution theory and to determine the age and helium content of stars. We study the eclipsing…
Despite astrophysical importance of binary star systems, detections are limited to those located in small ranges of separations, distances, and masses and thus it is necessary to use a variety of observational techniques for a complete view…
We have analyzed photometric and spectroscopic data of a sample of 14 spatially resolved pre-main-sequence binaries (separations 0.6" to 1.7") in the nearby (150 pc) low-mass star-forming regions of Chamaeleon, Lupus, and rho Ophiuchi. The…
The rapid rotation of Be stars is supposed to mainly originate from binary evolution. In recent years, more and more Be stars with helium (He) star companions have been discovered, which provides a significant opportunity to study binary…
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…
New photometry, including TESS data, have been combined with recent spectroscopic observations of the Orion Ib pulsating triple-star system VV Ori. This yields a revised set of absolute parameters with increased precision. Two different…
The origin of ultra-wide massive binaries (orbital separations $10^3-2\times 10^5$~AU) and their properties are not well characterized nor understood. Here we use the second Gaia data release to search for wide astrometric companions to…
It has now been known for over a decade that low-mass stars located in star-forming regions are very frequently members of binary and multiple systems, even more so than main sequence stars in the solar neighborhood. This high multiplicity…
We present the results of a binary population study in the Orion Nebula Cluster (ONC) using archival Hubble Space Telescope (HST) data obtained with the Advanced Camera for Surveys (ACS) in Johnson V filter (HST Proposal 10246, PI M.…