| Name | M 101 |
| Type | GX [Sc] |
| Other names | NGC5457 / PGC50063 / UGC8981 |
| Constellation | Ursa major |
| descr | M102 may be a duplicate obs. of M101; see Sawyer, JRASC 41, Nos 7&8, 1947. |
| RA | 14:03:12.4 |
| Dec | +54:20:58.0 |
| major_axis | 28.8' |
| minor_axis | 26.9' |
| position_angle | 26.0 |
| mag | 7.9 |
| surface_bright | 14.9 |