Charles T. Kowal (Palomar Observatory, California, USA) discovered this comet on a photographic plate exposed with the 122-cm Schmidt telescope on 1977 April 24.39. He estimated the magnitude as 16 to 17, and described the comet as diffuse with some condensation and a tail extending 2 arc minutes toward the northeast. It was then in Virgo. Images also appeared on plates exposed with the same telescope on the 25th and 26th.
The comet was already passed perihelion when found in 1977 and remained visible until June 17, when near magnitude 19.
Using observations obtained from April 24 through May 19, B. G. Marsden computed an elliptical orbit with a period of 18.6 years. As further observations were obtained the period was revised. During 1979 Marsden gave the period as 15.11 years and said the short observational arc brought about an uncertainty of about 2 weeks
Charles Thomas Kowal (November 8, 1940 – November 28, 2011) was an American astronomer known for his observations and discoveries in the Solar System. Kowal also discovered or co-discovered the periodic comets 99P/Kowal, 104P/Kowal, 134P/Kowal-Vavrova, 143P/Kowal-Mrkos, and 158P/Kowal-LINEAR. He was awarded the James Craig Watson Medal for his contributions to astronomy in 1979.