Messier Index/M103
| NGC 581 | |
|---|---|
| Observation data (J2000.0 epoch) | |
| Right ascension | 01h 33.2m |
| Declination | +60° 42′ |
| Distance | 8.5 kly () |
| Apparent magnitude (V) | 7.4 |
| Apparent dimensions (V) | 6.0' |
| Other designations | M103 |
Messier 103 (also known as M103, or NGC 581) is an w:open cluster in the w:constellation Cassiopeia. It was discovered by w:Pierre Méchain in w:1781. M103 is at a distance of about 8,000 w:light-years from w:Earth.