Periods and Eccentricities of Close Binary Stars

Abstract

EXAMINATION of the material in the Fifth Lick Catalogue of spectroscopic binaries, recently published by Moore and Neubauer¹, reveals a definite relation between periods of revolution P and eccentricities of orbits e for binaries with short periods if their components belong to the main sequence of stars. The accompanying diagram includes systems with spectral type of main component B9 to A7, each system being shown as a point with co-ordinates (log P,e). In fig. 1 are plotted binaries with two visible spectra, the mass of secondary exceeding two-thirds of the mass of primary (dots). Some few eclipsing variables with equal components and photometrically measured eccentricities are added (triangles). fig. 2 and 3 contain systems of binaries with one visible spectrum, the average masses of the secondaries ranging from about one-half (fig. 2) to about one sun mass (fig. 3).