Recent reviews have demonstrated that a wide ranging selection of objects emit a major proportion of their energy at wavelengths longer than 1 µm, including such intrinsically different objects as late type stars, Be stars, F supergiants and novae. In the majority of cases the infrared radiation has been interpreted in terms of thermal radiation from a circumstellar shell of solid ‘dust’ particles. Any attempt at a detailed comparison of theoretical energy distributions with observed infrared photometry encounters the problems of uncertainties in the absolute calibration, and limited accuracy of the observations.

Extensive observations of the spectra of the decametric radio bursts for Jupiter have been made by Riihimaa, principally at frequencies between 18 and 23 MHz and with frequency resolution of 50 kHz. These showed much fine frequency-time structure in the bursts but pointed to the need for higher frequency resolution and greater antenna sensitivity. This paper reports the results of observations made of the Jupiter bursts between February and April, 1972, using the Llanherne low frequency telescope (Ellis,).

Low frequency radio waves propagating in the interstellar medium are attenuated through absorption by thermal electrons, the optical depth being given by

where f is the radio frequency in MHz, the emission measure in cm-6 pc, and Te the electron temperature.

During 1971/72 the radioheliograph at Culgoora, N.S.W. was used to observe 30 bright galaxies at 80 MHz.