CV Serpentis (The sometimes eclipsing Wolf-Rayet system).

From spectroscopic observations of CV Ser made in 1970 an improved orbital period of 29.706 days has been determined. It is shown that the deep eclipse observed in 1962 occurred when the Woll-Rayet component was in conjunction, but behind, the B star. Orbital elements and masses are derived. The apparent circularity of the orbit and similarity to earlier spectroscopic data suggests that a change in the orbit cannot account for the greatly diminished eclipses. Key words: Woll-Rayet stars - spectroscopic binary - eclipsing binary