On the Radial Velocity-Curves for the Cepheid Variable Y OPHIUchi

Observations-Forty-four radial velocities of Y Ophiuchi were obtained by Albrecht at the Lick Observatory in 1905-1906, and 39, mostly by the writer, at Mount Wilson 111 1918-1934 inclusive. In addition he has measured 5 Lick spectrograms obtained by Jacobsen 111 1928. Curves of 1905-1906 and 1931-1932--The radial velocity-curve from the 1931-1932 observations gives a larger eccentricity, amplitude, and angle of periastron than does the curve from the 1905-1906 observations. Both curves, with their steep branches from minimum to maximum velocity, are abnormal for Cepheids. The period of i 7~ 1207 does not bring the epochs of the two curves into coincidence. Modification of the period from photometric data-A least-squares solution for the elements of light-variation gav