Variable Source of Radio Frequency Radiation in the Constellation of Cygnus

COSMIC or galactic noise was discovered by Jansky1 in 1931; but its exact origin has remained uncertain. It is generally supposed to originate from collisions in interstellar matter2; but there are divergencies between existing theory and experimental results, particularly at lower radio frequencies3. Hey, Parsons and Phillips4 discovered variations in the intensity of galactic noise from the direction of the constellation of Cygnus, with a period of about one minute—suggesting that this particular radiation has its origin in a discrete source.