Complex sentence: He discovered numerous comets, including the spectacular "Comet West" (C/1975 V1) and the periodic comets 76P/West-Kohoutek-Ikemura and 123P/West-Hartley.
Split into simpler sentences: He discovered numerous comets, including the spectacular "Comet West" (C/1975 V1). Also discovered some periodic comets, including 76P/West-Kohoutek-Ikemura and 123P/West-Hartley.