Upper Limit to the 11.4 m Flux of Saturn using VLBI

Searches continue for non-thermal continuum 1,2 and noise storm (ref. 3 and S. Ya. Braude, personal communication) radio emissions from Saturn which might be analogous to the decimetric and decametric emissions from Jupiter 4,5 . From wavelengths of 1 mm to 3.5 cm the measurements of Saturn can be fitted to a 140 K thermal blackbody curve. From 9 cm to longer wavelengths the equivalent blackbody temperature rises. Yerbury, Condon and Jauncey 1 measure a temperature of 400±65 K at 49.5 cm and 540±110 K at 94.3 cm using the Arecibo radio telescope. Observations of thermal emission at longer wavelengths are difficult because of the large collecting areas required. Gulkis 2 fits the existing emission curve with a deep, hot model atmosphere. Luthey 6 , however, considers the possibility of synchrotron radiation as a non-thermal explanation of the rising temperature curve at larger wavelengths. So far the observations of decametric noise storm emissions from Saturn seem to be negative 3 although Braude reports possible emissions of several tens of flux units at 25, 20 and 16.7 MHz.