Metre Wavelength Solar Radio Bursts with Periodic Modulation

Abstract

Observations of solar radio bursts in the frequency range 125-150 MHz are described. It is found that their properties are consistent with those observed for similar bursts in the 30-55 MHz range, except that all, rather than just a small proportion, showed periodic intensity maxima or fringes in the frequency-time plane. Fringe separation ?f was found to change with frequency between 30 and 150 MHz according to ?f 8 f 1.48, a result inconsistent with Faraday rotation as the cause of the fringes.