Solar Radio Asymmetry at 4-Metres Wave-length

IN 1948, Hey, Parsons and Phillips1 reported that at 4.1-metres wave-length bursts of radio emission, usually of a few minutes duration, occurred more often in association with flares on the eastern half of the sun's disk than on the western half. Subsequent observations have confirmed this conclusion. In a recent analysis of radio emissions at 1.5-metres wavelength, Dodson, Hedeman and Owren2 could find no evidence of this asymmetry. The following reasons may explain why they failed to observe the effect.