Related papers: High-resolution spectroscopic study of massive blu…

We compared stellar radii derived from asteroseismic scaling relations with those estimated using two independent surface brightness-colour relations (SBCRs) and Gaia DR3 parallaxes. We cross-matched asteroseismic and astrometric data for…

We develop Bayesian statistical methods for discovering and assigning probabilities to non-random (e.g., physical) stellar companions. These companions are either presently bound or were previously bound. The probabilities depend on…

We have conducted a 1.5 year-long variability study of the stars in the Cygnus OB2 association, the region in the northern hemisphere with the highest density of optically visible massive stars. The survey was conducted using four pointings…

We present the results of a search for wide binary systems among 783 members of three nearby young associations: Taurus-Auriga, Chamaeleon I, and two subgroups of Upper Scorpius. Near-infrared (JHK) imagery from 2MASS was analyzed to search…

Long-period binary systems containing a B-type hot subdwarf (sdB) and a main-sequence companion are thought to originate from binary interactions involving stable mass transfer from the red giant, the progenitor of the sdB, to the MS…

We present numerical simulations of the runaway fractions expected amongst O and Wolf-Rayet star populations resulting from stars ejected from binaries by the supernova of the companion. Observationally the runaway fraction for both types…

Close double degenerate binaries are one of the favoured progenitor channels for type Ia supernovae, but it is unclear how many suitable systems there are in the Galaxy. We report results of a large radial velocity survey for double…

Multiplicity among massive stars represents a major uncertainty in stellar evolution theory, because the extra physical processes that it introduces significantly impacts each star's structure. While multiplicity of O-type stars is fairly…

We present the results of a J, H, and K photometric variability survey of the central 0.78 square degrees of the young OB association Cygnus OB2. We used data observed with the Wide-Field CAMera at the United Kingdom Infrared Telescope in…

We present a study of blue straggler stars (BSSs) of open cluster NGC 7142 using AstroSat/UVIT data and other archival data. Using a machine learning-based algorithm, ML-MOC, on Gaia DR3 data, we find 546 sources as cluster members. Based…

The Cygnus OB2 Association is one of the nearest and largest collections of massive stars in the Galaxy. Situated at the heart of the "Cygnus X" complex of star-forming regions and molecular clouds, its distance has proven elusive owing to…

The first directly imaged exoplanets indicated that wide-orbit giant planets could be more common around A-type stars. However, the relatively small number of nearby A-stars has limited the precision of exoplanet demographics studies to…

Massive OB stars are critical to the ecology of galaxies, and yet our knowledge of OB stars in the Milky Way, fainter than $V \sim 12$, remains patchy. Data from the VST Photometric H$\alpha$ Survey (VPHAS+) permit the construction of the…

We recently identified a substantial population of galaxies at z>2 with red rest-frame optical colors. These distant red galaxies (DRGs) are efficiently selected by the simple observed color criterion J-K>2.3. In this paper we present NIR…

While the majority of massive stars have a stellar companion, most pulsars appear to be isolated. Taken at face value, this suggests that most massive binaries break apart due to strong natal kicks received in supernova explosions. However,…

As part of an investigation into the high mass end of the initial mass-final mass relation we performed a search for new white dwarf members of the nearby (172.4 pc), young (80-90 Myr) $\alpha$ Persei open star cluster. The photometric and…

Nearby stellar streams carry unique information on the dynamical evolution and disruption of stellar systems in the Galaxy, the mass distribution in the disk, and provide unique targets for planet formation and evolution studies. We revisit…

New optical MK classification spectra have been obtained for 14 OB star candidates identified by Comeron et al. (2002) and presumed to be possible members of the Cyg OB2 cluster. All 14 candidate OB stars observed are indeed early-type…

Gaia Data Release 2 (DR2) was used to select a sample of 211 central stars of planetary nebulae (CSPNe) with good quality astrometric measurements, that we refer to as GAPN, Golden Astrometry Planetary Nebulae. Gaia astrometric and…

The extremely accurate estimates of stellar variability and radial velocity in the Gaia Data Release 3 (Gaia DR3) have enabled us to examine the close binarity and radial velocity (RV) of central stars (CSs) of planetary nebulae (PNe). This…