Related papers: The primordial binary population II: Recovering th…

Low-mass stars 0.1 ~< M ~< 1 Msun) in OB associations are key to addressing some of the most fundamental problems in star formation. The low-mass stellar populations of OB associations provide a snapshot of the fossil star-formation record…

Almost all massive stars have bound stellar companions, existing in binaries or higher-order multiples. While binarity is theorized to be an essential feature of how massive stars form, essentially all information about such properties is…

Observations of binaries have traditionally provided the means for ascertaining stellar masses. Here, we use the published data on 8 pre-main-sequence pairs to gauge the accuracy of our own, recently calculated, evolutionary tracks (Palla &…

We present the Class I protostellar binary separation distribution based on the data tabulated in the companion paper. We verify the excess of Class I binary stars over solar-type main-sequence stars, especially at separations beyond 500…

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…

We perform evolutionary calculations of binary stars to find progenitors of systems with parameters similar to the recurrent nova U Sco. We show that a U Sco-type system may be formed starting with an initial binary system which has a…

We study the formation of massive Population III binary stars using a newly developed radiation hydrodynamics code with the adaptive mesh refinement and adaptive ray-tracing methods. We follow the evolution of a typical primordial…

Binary stars play a crucial role in our understanding of the formation and evolution of star clusters and their stellar populations. We use Gaia Data Release 3 to homogeneously analyze 78 Galactic open clusters and the unresolved binary…

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.…

Recent observations of binary stars in the Galactic field show that the binary fraction and the mean orbital separation both decrease as a function of decreasing primary mass. We present $N$-body simulations of the effects of dynamical…

We determine the fraction of G-dwarf stars that could host stable planetary systems based on the observed properties of binaries in the Galactic field, and in various postulated primordial binary populations, which assume that the…

We summarize observational results on the stellar population and star formation history of the Scorpius-Centaurus OB Association (Sco OB2), the nearest region of recent massive star formation. It consists of three subgroups, Upper Scorpius…

Observations and theory suggest that star clusters can form in a subvirial (cool) state and are highly substructured. Such initial conditions have been proposed to explain the level of mass segregation in clusters through dynamics, and have…

We analyze the spatial distributions of young stars in Taurus-Auriga and Upper Sco as determined from the two-point correlation function (i.e. the mean surface density of neighbors). The corresponding power-law fits allow us to determine…

We discuss the properties of companions to B stars in the Scorpius-Centaurus association (age ~15 Myr, 181 B-stars). We gathered available data combining high contrast imaging samples with evidence of companions from Gaia, from eclipsing…

We searched for binary companions to 20 young brown dwarfs in the Upper Scorpius association (145 pc, 5 Myr, nearest OB association) with the the Laser Guide Star adaptive optics system and the facility infrared camera NIRC2 on the 10 m…

The dynamical influence of binary companions is expected to profoundly influence planetary systems. However, the difficulty of identifying planets in binary systems has left the magnitude of this effect uncertain; despite numerous…

We present the first multiplicity-dedicated long baseline optical interferometric survey of the Scorpius-Centaurus-Lupus-Crux association. We used the Sydney University Stellar Interferometer to undertake a survey for new companions to 58…

Binary stars play a vital role in astrophysical research, as a good fraction of stars are in binaries. Binary fraction (BF) is known to change with stellar mass in the Galactic field, but such studies in clusters require binary…

Massive binary stars may constitute a substantial fraction of progenitors to supernovae and gamma-ray bursts, and the distribution of their orbital characteristics holds clues to the formation process of massive stars. As a contribution to…