M 103By astrored / November 6, 2023 M102 . . Index . . M104 Messier 103 M 103 (NGC 581) Open Cluster in Cassiopeia. RA=01 33.2, Dec=+60 42. 7.4 mag, dist=8 kly. M103 page; DSSM page Hartmut Frommert ([email protected]) Christine Kronberg ([email protected]) Last Modification: 7 Apr 1998, 22:15 MET