M103
open cluster · Cassiopeia · 7.4ᵐ
A Messier catalogue object — open cluster in Cassiopeia.
Notable facts
About 1/5 the apparent diameter of the Moon.
In brief
Which constellation is M103 in?
M103 lies in Cassiopeia.
Is M103 visible to the naked eye?
7.4ᵐ — visible with binoculars.
When is the best time to observe M103?
Best observed in October.
Data
- RA / Dec (J2000)
- 1h 33m · +60° 42′
- Type
- open cluster
- Constellation
- Cassiopeia
- How to observe
- 7.4ᵐ — visible with binoculars
- Angular size
- 6′
- Designation
- M103 · NGC 581
Observing tip
Best in binoculars or a telescope at low power, so the whole cluster fits in the field of view.
Altitude above the horizon by latitude
| Latitude | Maximum altitude | Rise azimuth |
|---|---|---|
| +60° | 89° · never sets | — |
| +55° | 84° · never sets | — |
| +45° | 74° · never sets | — |
| +30° | 59° · never sets | — |
| 0° | 29° | 29° |
| −35° | never rises | — |
Geometric altitude at upper culmination, atmospheric refraction not included. Positive latitudes are in the northern hemisphere.
Culmination time by month
| Month | Culmination |
|---|---|
| January | 17:48 |
| February | 15:40 |
| March | 13:55 |
| April | 12:02 |
| May | 10:07 |
| June | 08:01 |
| July | 05:57 |
| August | 03:56 |
| September | 02:03 |
| October | 00:15 |
| November | 22:14 |
| December | 20:05 |
Upper culmination in local solar time — no time-zone or daylight-saving correction applied.