SEARCH FOR FORCED-OSCILLATIONS IN BINARIES .2. BETA-SCORPII-A - NEW PHYSICAL PARAMETERS AND A SEARCH FOR LINE-PROFILE VARIABILITY

We present new spectroscopic data and physical parameters for the earl y-type binary system beta Sco A. Radial velocity measurements of Retic on spectra have been made using both cross-correlation and disentangli ng techniques. Spectroscopic orbits, based on the new data and publish ed radial velocities are presented. The orbital period and apsidal mot ion rate have been refined using 603 radial velocities covering a time interval of 84 years. The anomalistic period is 6.828245 +/- 0.000009 days, and the apsidal motion rate is omega = 0.00131 +/- 0.00004 degr ees per day. The first visual spectroscopic orbit for the system is gi ven here as well, from which we derive a parallax for the system of 0. '' 0070 +/- 0.'' 0001 corresponding to a distance of 143 +/- 3 pc. Thi s has allowed us to compute the absolute dimensions and mean internal structure constant for the system. We find, for the primary and second ary respectively, masses, radii, and effective temperatures of: m(p)/m . = 13.5 +/- 0.9, m(s)/m. = 9.6 +/- 0.4, r(p)/r. = 6.8 +/- 0.4, r(s)/r . = 4.2 +/- 0.3, T-p = 28000 +/- 2000 K, and T-s = 26400 +/- 2000 K. T he corresponding spectral types of the components are B0.5IV-V and B1. 5V. Line photometry produced from the disentangling solutions suggests the presence of eclipses in beta Sco A, which must be verified throug h systematic photometry. We also present a tentative detection of poss ible beta Cep -type line profile variability in the secondary.