Related papers: Sub-systems in nearby solar-type wide binaries
We present updated results of a high-resolution, magnitude limited (Ks<12 mag) imaging survey of nearby low-mass M6.0-M7.5 field stars. The observations were carried out using adaptive optics at the Gemini North, VLT, Keck II, and Subaru…
We describe an astrometric and spectroscopic campaign to confirm the youth and association of a complete sample of candidate wide companions in Taurus and Upper Sco. Our survey found fifteen new binary systems (3 in Taurus and 12 in Upper…
To improve the statistics of hierarchical multiplicity, secondary components of wide nearby binaries with solar-type primaries were surveyed at the SOAR telescope for evaluating the frequency of subsystems. Images of 17 faint secondaries…
We report on our analysis of HST/NICMOS snapshot high resolution images of 255 stars in 201 systems within ~10 parsecs of the Sun. Photometry was obtained through filters F110W, F180M, F207M, and F222M using NICMOS Camera 2. These filters…
We present the results of a high-resolution imaging survey of 12 brown dwarfs and very low mass stars in the closest (~145 pc) young (~5 Myr) OB association, Upper Scorpius. We obtained images with the Advanced Camera for Surveys/High…
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…
Stellar systems consisting of three or more stars are not an uncommon occurrence in the Galaxy. Nearly 50% of solar-type wide binaries with separations >1000 au are actually higher-order multiples with one component being a close binary.…
We report the discovery of a very low mass binary system (primary mass <0.1 Msol) with a projected separation of ~5100 AU, more than twice that of the widest previously known system. A spectrum covering the 1-2.5 microns wavelength interval…
We present preliminary results from a coronagraphic survey of young nearby Sun-like stars using the Palomar and Keck adaptive optics systems. We have targeted 251 solar analogs (F5-K5) at 20-160 pc from the Sun, spanning the 3-3000 Myr age…
Be stars are widely considered to be the product of binary interaction. However, whether all Be stars are formed via binary interaction is unclear, and detailed estimates of the multiplicity of Be stars and characterization of their…
A significant fraction of, and possibly all, stars form in binary or multiple systems. For Solar-mass stars in the Galactic field, the distribution of orbital separations is log-normal over seven orders of magnitude, from $10^{-2} - 10^5$…
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…
We present updated results from our near-infrared long-baseline interferometry (LBI) survey to constrain the multiplicity properties of intermediate-mass A-type stars within 80 pc. Previous adaptive optics surveys of A-type stars are…
We present results of a high-resolution, near-infrared survey of 41 nearby, young (<~300 Myr) M0-M5.0 dwarfs using the Altair natural guide star adaptive optics system at the Gemini North telescope. Twelve of the objects appear to be…
We have used the NICMOS NIC1 camera on the Hubble Space Telescope to obtain high angular resolution images of 51 ultracool dwarfs in the immediate Solar Neighbourhood. Nine systems are resolved as binary, with component separations from 1.5…
A combination of high-resolution and wide-field imaging reveals two binary stars and one triple star system among the sample of the first 11 stars with planets detected by radial velocity variations. High resolution speckle or adaptive…
We combine a catalog of wide binaries constructed from Gaia DR2 with [Fe/H] abundances from wide-field spectroscopic surveys to quantify how the binary fraction varies with metallicity over separations $50 \lesssim s/{\rm AU} \lesssim…
Radial velocity (RV) monitoring of solar-type visual binaries has been conducted at the CTIO/SMARTS 1.5-m telescope to study short-period systems. Data reduction is described, mean and individual RVs of 163 observed objects are given. New…
We conducted a survey of nearby binary systems composed of main sequence stars of spectral types F and G in order to improve our understanding of the hierarchical nature of multiple star systems. Using Robo-AO, the first robotic adaptive…
Observations at various wavelengths of late B-type stars exhibiting strong overabundances of the chemical elements Hg and Mn in their atmospheres indicate that these stars are frequently found in binary and multiple systems. We intend to…