The Position and Stokes Parameters in the Integrated 21-CENTIMETER Radio Emission of Jupiter and Their Variation with Epoch and Central Meridian Longitude

Interferometer observations of Jupiter using short antenna spacings were made in 1968 and 1970 at 21.1 cm wavelength and in 1971 at 18.7 cm. The flux density, centroid position, and complete polarization state of the integrated emission were determined at many different central meridian longitudes. A small displacement of the emission centroid from the center of the planet may have been detected. Of greater importance, perhaps, is that a displacement larger than about 0.13 radii is ruled out. The observations confirm the slow decrease in flux density over a period of years, and extend the time base to 11 years, during which there has been no start of a recovery from the decline. The variation of flux density and polarization with central meridian longitude changed character in several respects from earlier observations. Some, but not all, of these changes can be explained by the change in our aspect angle DE since the earlier observations. Subject headings: Jupiter - polarization - radio radiation, planetary