Named in honor of Roland Wielen (1938– ), German astronomer, director of the Astronomisches Rechen-Institut in Heidelberg, professor of theoretical astronomy at Heidelberg University since 1985, and from 1978 to 1985 professor of astronomy and astrophysics at the Berlin Technical University. His main work covers the fields of the stellar dynamics (the luminosity function of nearby stars, kinematics and dynamics of galaxies, dynamical evolution of star clusters and of clusters of galaxies) and astrometry. He has also worked on problems of galactic structure and served as president of IAU Commission 33 from 1982 to 1985. (M 18143) _ _.