A Southern Hemisphere Survey of the Radiants of Sporadic Meteors

Abstract

A further survey of sporadic meteor activity, from December 1956 to August 1958, has been made with 67 mc/s narrow-beam equipment operated at a limiting line density close to 10 11 electrons/cm. Analysis of the echo rates suggests that the sporadic radiant distribution may be sharply divided into two components. One component is concentrated towards the apex and corresponds to a distribution of orbits uniform in heliocentric co-ordinates except for a moderate preponderance of direct over retrograde orbits. The other component lies close to the plane of the ecliptic, with radiants strongly concentrated in two regions centred on longitudes ± 68° from the apex. No change is apparent in the radiant distribution as the limiting sensitivity is lowered from the 3rd to the 7th visual magnitude.