Statistical properties of spectroscopic binary stars

Autor: Sake J. Hogeveen
Rok vydání: 1992
Předmět:
Zdroj: Astrophysics and Space Science. 193:29-46
ISSN: 1572-946X
0004-640X
DOI: 10.1007/bf01070198
Popis: As part of a study of the mass-ratio distribution of spectroscopic binary stars, the statistical properties of the systems in theEighth Catalogue of the Orbital Elements of Spectroscopic Binary Stars, compiled by Battenet al. (1989), are investigated. Histograms are presented of the distributions of various parameters of the systems in the catalogue as a whole, and compared to those of the previous edition. Histograms of binaries of various spectral types are presented. It is noted that the early-type binaries in the catalogue have on average higher radial-velocity amplitudes, shorter periods, and smaller semi-major axes than late-type binaries. Late-type binaries have relatively more eccentric orbits. Whether the differences noticed between the early- and late-type binaries have any significance with respect to the population of binary stars in the Galaxy is not clear, because it is very hard to assess the extent to which the catalogue is a statistically representative and complete sample. The distribution of semi-major axesa 1 sini varies considerably among different subsamples. The mass-ratio distribution of single-lined spectroscopic binaries is, for all (sub-)samples, characterized by a decrease in the number of systems according to a power law asq→1, forq=M sec/M prim>0.25. The mass-ratio distribution of double-lined spectroscopic binaries (SBII) is, for all (sub-)samples but one, characterized by an increase in numbers according to a power law, asq→1. The exception to this general behaviour is the sample of SBII systems with magnitudesm≤5 m , which has its maximum atq≈0.65. The distributions are presented ‘as they are’, without corrections for selection effects.
Databáze: OpenAIRE
Externí odkaz: