Low-mass visual companions to nearby G-dwarfs

Abstract

Complete census of wide visual companions to nearby G-dwarf stars can be achieved by selecting candidates from the 2MASS Point-Source Catalog and checking their status by second-epoch imaging. Such data are obtained for 124 candidates with separations up to 20", 47 of which are shown to be new physical low-mass stellar companions. A list of visual binaries with G-dwarf primaries is produced by combining newly found companions with historical data. Maximum likelihood analysis leads to the companion frequency of 0.13+-0.015 per decade of separation. The mass ratio is distributed almost uniformly, with a power-law index between -0.4 and 0. The remaining uncertainty in the index is related to modeling of the companion detection threshold in 2MASS. These findings are confirmed by alternative analysis of wider companions in 2MASS, removing the contamination by background stars statistically. Extension of this work will lead to a complete detection of visual companions - a necessary step towards reaching unbiased multiplicity statistics over the full range of orbital periods and, eventually, understanding the origin of multiple systems.

Accepted for publication in Astronomical Journal. 24 pages, 4 tables, 15 figures

References in corpus (8)

• A Survey of Stellar Families: Multiplicity of Solar-Type Stars
• Discoveries from a Near-infrared Proper Motion Survey using Multi-epoch 2MASS Data
• The Palomar/Keck Adaptive Optics Survey of Young Solar Analogs: Evidence for a Universal Companion Mass Function
• Mapping the Shores of the Brown Dwarf Desert I.: Upper Scorpius
• New Distant Companions to Known Nearby Stars. II. Faint companions of Hipparcos stars and the frequency of wide binary systems
• The multiplicity of exoplanet host stars - New low-mass stellar companions of the exoplanet host stars HD125612 and HD212301
• Common Proper Motion Companions to Nearby Stars: Ages and Evolution
• Sub-systems in nearby solar-type wide binaries

Cited by in corpus (18)

• Stellar Multiplicity
• From binaries to multiples II: hierarchical multiplicity of F and G dwarfs
• Mapping the Shores of the Brown Dwarf Desert II: Multiple Star Formation in Taurus-Auriga
• A survey of the high order multiplicity of nearby solar-type binary stars with Robo-AO
• A Triple Protostar System Formed via Fragmentation of a Gravitationally Unstable Disk
• Wide companions to Hipparcos stars within 67 pc of the Sun
• From binaries to multiples I: Data on F and G dwarfs within 67 pc of the Sun
• Discovery of an equal-mass "twin" binary population reaching 1000+ AU separations
• CARMENES input catalogue of M dwarfs II. High-resolution imaging with FastCam
• The VLT/NaCo Large program to probe the occurrence of exoplanets and brown dwarfs in wide orbits: I- Sample definition and characterization
• Speckle interferometry at SOAR in 2014
• Elemental abundances of low-mass stars in nearby young associations: AB Doradus, Carina Near, and Ursa Major
• Stellar Multiplicity and Debris Disks: An Unbiased Sample
• The population of white dwarf-main sequence binaries in the SDSS DR 12
• The role of the turbulence driving mode for the Initial Mass Function
• Spectroscopic orbits of subsystems in multiple stars. VIII
• Overlooked wide companions of nearby F stars
• A Complete Analysis of Subgiant Stellar Systems III: Hip70868