Career
He was one of the most successful visual discoverers of novae and comets. Initially, his interest in astronomy involved observation of meteors and meteor showers, but in 1953 he decided to start searching for comets and in 1955 began searching for novae. His technique was to memorize the patterns of thousands of stars, so that he would visually recognize any intruder.
In 1959 he discovered comet C/1959 Q1 (Alcock), the first comet discovered in Britain since 1894, and only five days later discovered another, C/1959 Q2 (Alcock).
He discovered two more comets in 1963 and 1965. He later discovered his first nova, Nova Delphini 1967 (Human Resources Delphini), which turned out to have an unusual light-curve.
He discovered two more novae, LV Vul (in 1968) and V368 Sct (in 1970). He found his fifth and final comet in 1983: C/1983 H1 (IRAS-Araki-Alcock).
In 1991 he found the nova V838 Her.