Bennett's interest in astronomy began early when his mother showed him the starry sky with the
Southern Cross and the
planets on the way home from evening church visits and told him about her observation of
Halley's Comet on its return in 1910. After the war he started looking for comets with a 60 mm
refractor, and from 1958 he observed the new
artificial satellites. For this purpose, he bought a light 125 mm refractor with an
altazimuth mount in 1961, which later became his favorite instrument. He became a member of the
Astronomical Society of Southern Africa and the
British Astronomical Association at an early age. Although he discovered
comets as early as the 1960s, he was either not the first discoverer, or the comets he found were short-lived and could not be observed again. During this time (1969 to 1974) he systematically compiled a catalog of 152 objects in the southern sky that could be mistaken for a comet. This list, later called the Bennett catalog, is still today a valuable aid for comet hunters, a "southern
Messier catalog". Every year he spent some 150 hours looking for comets in the backyard of his house in Pretoria and by chance discovered on 16 July 1968 an unusual appearance in the galaxy
Messier 83 (NGC 5236) in the constellation
Hydra. This was recognized shortly afterwards by professional astronomers as a
supernova (SN 1968L). Bennett was the first person to visually discover a supernova since the invention of the telescope. With his 125 mm refractor he finally discovered his first comet,
C/1969 Y1 (Bennett), after a search for more than 333 hours on 28 December 1969. This became a "Great Comet" that could be seen with the naked eye the following year. His second comet discovery occurred on 13 November 1974 after a further 482 hours of search. This was the inconspicuous
C/1974 V2 (Bennett). In later years he bought a Celestron C-8, but despite 30 to 40 hours of searching annually for the next 10 years, he had no further success in hunting comets, partially due to increasing light pollution. In addition to comets, he was also interested in meteors and variable stars. In the years before his death, he had to give up observing entirely and donated his famous 125 mm refractor to the
University of South Africa. == Discoveries ==