Named in honor of Grzegorz Sitarski {1932– }, astronomer at the Polish Academy of Sciences, well known for his studies of the motions of comets, including consideration of nongravitational effects. He has recently succeeded in dynamically linking the observations made of (1862) Apollo and (2101) Adonis in the 1930s and the 1970s. Currently involved in an extensive program of new orbit determinations of one-apparition comets, he was (1979–1982) President of IAU Commission 20. (M 5523) _ _.