The apparent sizes of the Jovian decametric radio sources

Abstract

During 1963 and 1964 measurements were made of the angular sizes of the sources of Jovian radio bursts, at a frequency of 19·7 Mc/s, using interferometers with spacings up to 12700 > lambda. The measured source sizes were mostly in the range 10-15 sec of arc, but it seems likely that these apparent sizes are produced by interplanetary scattering and that the intrinsic size may be much smaller. It is suggested that many of the "bursts" received from Jupiter are produced by a diffraction or focusing process in interplanetary space and so may be analogous to the interplanetary scintillations recently reported by Hewish, Scott, and Wills (1964). If so, the real angular size of the Jupiter source would probably be less than 1 sec of arc.