Evidence of Echoes in the Solar Corona from a New Type of Radio Burst

Abstract

A new spectral type of solar radio burst is described. The bursts contain two elements, the second being a repetition of the first after a delay of $$ sec. In each element the frequency increases with time at a rate of 2?8 Mc/s per sec. The bursts are of very short duration and are confined to the longer metre wavelengths. Occasionally they occur within, and evidently form part of the structure of, a burst of spectral type III.