Measurements of the integrated Stokes parameters of compact radio sources

The complete state of the integrated radiation from several compact radio sources was measured at three frequencies and at several epochs: 1420 MHz (1971.0), 1602 MHz (1971.1), and 5000 MHz (1971.5,1971.8, and 1972.0). The latter represents the beginning of a program, still in progress, to monitor selected sources periodically at 5000 MHz. Mthough we were primarily interested in circular polarization, all four Stokes parameters were, in fact, obtained, and all of the results are presented herein. Of 54 radio sources observed in one or more of the observing sessions, circular polarization was detected in 12 and suspected in six others. It appears that magnetic field estimates based on the observed circular polarization are significantly larger than those deduced from synchrotron self-absorption.