Spectrographic Observations of the Eclipsing Binaries RZ Comae, V 502 Ophiuchi, RV Corvi, and BF Virginis.

Abstract

Two systems of the W UMa type-RZ Corn and V 502 Oph-show double lines which lead to mass ratios of a = 2.1 and a = 2.5, respectively. The individual mass functions are: for RZ Corn, mi sin3 i = 1.58 0, m2 sinai = 0.75 0; for V 502 Oph, m1 sin3 i = 1.22 0, m2 sin3 i = 0.49 0. The large values of a show that one or possibly both components of the W UMa systems depart from the mass-luminosity relation. The other two systems-RV Cry and BF Vir-have single lines, and their mass functions are f(m) = 0.033 0 and 0.025 0, respectively. These mass functions are small, and they show that even for periods as short as 0.75 and 0.64 day, respectively, we encounter the same difficulty of reconciling the Algol- type binaries with the "normal" spectroscopic binaries as we encountered previously for systems of longer periods. The former have systematically much smaller values of K1 than do the ordinary spectro- scopic binaries. This, in turn, leads to the conclusion that very often the fainter companions of the typical Algol systems depart appreciably from the mass-luminosity relation: they are either too luminous for their mass or not sufficiently massive for their luminosity,