Named in honor of Philip D. Nicholson (1951– ), professor of astronomy at Cornell University, an Australian by birth. Nicholson’s research centers on the orbital dynamics of planetary ring systems and natural satellites, and infrared observational studies of planets, their satellites and rings. He has also investigated the dynamics of a planetary system around the pulsar PSR 1257+12 and has studied the zodiacal dust bands. Nicholson is codiscoverer of two irregular satellites of Uranus and is currently editor of the journal Icarus, which is devoted to planetary science. (M 32790) _ _.