Related papers: The massive star binary fraction in young open clu…
Previous studies on the rotation of Sun-like stars revealed that the rotational rates of young stars converge towards a well-defined evolution that follows a power-law decay. It seems, however, that some binary stars do not obey this…
We investigate the hypothesis that stars form in aggregates of binary systems and that the dynamical evolution of these aggregates leads to the observed properties of binary stars in the Galactic field. We assume that the initial…
(Abridged) The open cluster NGC 1893, illuminating the HII region IC410, contains a moderately large population of O-type stars and is one of the youngest clusters observable in the optical range. We have probed the stellar population of…
On the basis of the best available member list and duplicity information, we have studied the radial structure of Praesepe and of the very young open cluster NGC 6231. We have found mass segregation among the cluster members and between…
The formation of massive stars remains poorly understood and little is known about their birth multiplicity properties. Here, we investigate the strikingly low radial-velocity dispersion measured for a sample of 11 massive pre- and…
Binary stars plays important role in the evolution of stellar populations . The intrinsic binary fraction ($f_{bin}$) of O and B-type (OB) stars in LAMOST DR5 was investigated in this work. We employed a cross-correlation approach to…
The recent sample of 21 detached eclipsing binaries in the Small Magellanic Cloud (Harries et al. 2003, Hilditch et al. 2005) provides a valuable test of the binary mass function for massive stars. We show that 50% of detached binaries have…
NGC 5139 ($\omega$ Cen), is the closest candidate of a Nuclear Star Cluster that has been stripped of its host galaxy in the Milky Way. Despite extensive studies through the last decades, many open questions about the cluster remain,…
This work presents the first high-precision variability survey in the field of the intermediate-age, metal--rich open cluster NGC 6253. Clusters of this type are benchmarks for stellar evolution models. Continuous photometric monitoring of…
We present orbits for 24 binaries in the field of open cluster NGC 2516 (~150 Myr) and 13 binaries in the field of open cluster NGC 2422 (~130 Myr) using results from a multi-year radial velocity survey of the cluster cores. Six of these…
The majority of close massive binary stars with initial periods of a few days experience a contact phase, in which both stars overflow their Roche lobes simultaneously. We perform the first dedicated study of the evolution of massive…
We find that the emission line object OGLEJ005039.05-725751.4, a member of the cluster OGLE-CL SMC 64, exhibits a peculiar light curve pattern repeating with a recurrence time of 141.45 days. The light curve resembles periodic outbursts…
Analysis of radial velocities of two narrow absorption components in the Mg II 4481 A line demonstrated that the secondary of the Be star omicron Cas is indeed a close binary system composed of two B7 stars orbiting each other with a period…
We present detailed analyses of updated eclipse timing diagrams for 32 contact binary merger candidates in the Galactic bulge. The photometric data was obtained from 2016 to 2021 using the Korea Microlensing Telescope Network (KMTNet) with…
The stellar mass-luminosity relation is poorly constrained by observations for high mass stars. We describe our program to find eclipsing massive binaries in the Magellanic Clouds using photometry of regions rich in massive stars, and our…
Characterization of the binary fractions in star clusters is of fundamental importance for many fields in astrophysics. Observations indicate that the majority of stars are found in binary systems, while most stars with masses greater than…
As many as 10\% of OB-type stars have global magnetic fields, which is surprising given their internal structure is radiative near the surface. A direct probe of internal structure is pulsations, and some OB-type stars exhibit pressure…
We have carried out a major survey for visual binaries towards the Orion Nebula Cluster using HST images obtained with an H-alpha filter. Among 781 likely ONC members more than 60" from theta-1 Ori C, we find 78 multiple systems (75…
We report the discovery of two binary systems, each consisting of a slightly bloated G-type main-sequence star and an unseen companion, identified through photometric data from TESS and radial velocity variation from Gaia. High-resolution…
We present the results of a variable stars search in the field of the old open cluster NGC 2204. Five new variables were found, four of them being eclipsing binaries. The sample includes a detached binary located at the turnoff, a W UMa -…