|Observation data (|
|10 thousand |
|Apparent dimensions (V)||6.0'|
|Other designations||NGC 581|
Messier 103 (also known as M103, or NGC 581) is an
After the discovery of
Messier 103 has been rated by the Astronomical League as an easy object to find and the cluster is visible even with the use of binoculars. M103 can be seen as a nebulous fan-shaped patch, and optically is about a 6 arcminute circle, or about a fifth the diameter of the full moon. In order to find M103, it is suggested that the observer center their binoculars on Ruchbah or the bottom left star of the visible “W” in Cassiopeia. The cluster will appear as a hazy patch about 1/3 of a field toward 45 Epsilon Cassiopeia.