ZETA(2)-CORONAE-BOREALIS, A SPECTROSCOPIC TRIPLE SYSTEM INCLUDING AN ASYNCHRONOUS CLOSE BINARY

Using the 1-m telescope at Fitter Observatory, we took 36 observations of zeta(2) Coronae Borealis with a fiber-fed echelle spectrograph. Fr om these observations, zeta(2) CrB was found to be a triple system and a new spectroscopic orbit was calculated. This orbit has two periods, a 1.72357-day period for the inner binary composed of zeta(2) CrB A a nd B and a 251-day period for the outer binary composed of zeta(2) CrB AB and C. The inner binary is a double-lined spectroscopic binary com posed of two B7 V stars. The inner binary's center of mass (zeta(2) Cr B AB) describes a long-period single-lined variation identified with t he outer binary. The inner binary period is significantly shorter than the 12.5842-day period previously calculated by Abhyankar and Sarma ( MNRAS, 133, 437, 1966). The inner binary possesses an essentially circ ular orbit (e=0.01) while the outer binary has an eccentric orbit (e=0 .48). From the widths of their Si II 6371 Angstrom lines, the nu sin i 's were calculated to be 46+/-7 km s(-1) for zeta(2) CrB A and 7.5+/-2 km s(-1) for zeta(2) CrB B. As zeta(2) CrB A and B have similar masse s, their different rotational velocities make this system a sensitive test of synchronization theories.