Related papers: Are All Hot Subdwarf Start in Close Binaries?
Wide gravitationally bound pairs of stars can be formed from adjacent prestellar cores that happen to move slowly enough relative to each other. These binaries are remnants of the primordial clustering. It is shown that the expected…
Galactic globular clusters are old, dense star systems typically containing 10\super{4}--10\super{7} stars. As an old population of stars, globular clusters contain many collapsed and degenerate objects. As a dense population of stars,…
The complexity of composite spectra of close binary star system makes study of the spectra of their component stars extremely difficult. For this reason there exists very little information on the photospheric chemical composition of stars…
Observations of main sequence stars conducted over the last several decades have clearly shown that something like 50 per cent of stars of spectral types G and F occur in multiple systems. For earlier spectral types, the incidence of…
Compact Galactic binaries where at least one member is a white dwarf or neutron star constitute the majority of individually detectable sources for future low-frequency space-based gravitational-wave (GW) observatories; they also form an…
The preponderance of binary systems in all known stellar populations makes them exciting dynamical agents for research on topics as varied as star formation, star-cluster dynamics and the interiors of young and old stars. Today we know that…
We investigated the statistical properties of both cool and hot starspots in eclipsing binary stars. The starspot and binary parameters for contact and semi-detached systems were collected from literature, which were determined on the basis…
We present analysis of Hubble Space Telescope images of 82 nearby field late-M and L dwarfs. We resolve 13 of these systems into double M/L dwarf systems and identify an additional possible binary. Combined with previous observations of 20…
Massive binary stars undergo qualitatively different evolution when the two components are similar in mass ('twins'), and the abundance of twin binaries is therefore important to understanding a wide range of astrophysical phenomena. We…
Hot subluminous stars can be roughly divided into B- and O-types. Unlike the latter many sdBs are found in close binaries, indicating that binary evolution plays a vital role. Recent NLTE spectral analyses revealed that an evolutionary link…
Massive stars can be found in wide (hundreds to thousands AU) binaries with other massive stars. We use $N$-body simulations to show that any bound cluster should always have approximately one massive wide binary: one will probably form if…
Rapid rotation is a fundamental characteristic of classical Be stars and a crucial property allowing for the formation of their circumstellar disks. Past evolution in a mass and angular momentum transferring binary system offers a plausible…
The project Massive Unseen Companions to Hot Faint Underluminous Stars from SDSS (MUCHFUSS) aims at finding hot subdwarf stars with massive compact companions (white dwarfs with masses $M>1.0 {\rm M_{\odot}}$, neutron stars or black holes).…
We present the culmination of our near-infrared survey of the optically spectroscopically identified white dwarf stars from the McCook & Sion catalog, conducted using photometric data from the Two Micron All Sky Survey final All Sky Data…
Only a handful of binary central stars of planetary nebulae (PNe) are known today, due to the difficulty of detecting their companions. Preliminary results from radial velocity surveys, however, seem to indicate that binarity plays a…
Subluminous B stars (sdBs) form the extremely hot end of the horizontal branch and are therefore related to the blue horizontal branch (BHB) stars. While the rotational properties of BHB stars have been investigated extensively, studies of…
Massive stars are born predominantly as members of binary (or higher multiplicity) systems, and the presence of a companion can significantly alter their life and final fate. Therefore, any observed sample of massive stars or associated…
The occurrence of planets in binary star systems has been investigated via a variety of techniques that sample a wide range of semi-major axes, but with a preponderance of such results applicable to planets with semi-major axes less than a…
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…
I have undertaken a comprehensive statistical investigation of the ultracool dwarf companion distribution (spectral type M6 and later). Utilizing a Bayesian algorithm, I tested models of the companion distribution against data from an…