Ptolemy Cluster:
open star cluster
Ptolemy Cluster is a open star cluster located in the constellation Scorpius . Ptolemy Cluster is magnitude 3.30*, and is 1° ' 20' in size. For reference, the full moon is 30' (arc minutes) or 0.5° in size.
- Name:
- Ptolemy Cluster
- Type:
- open cluster
- Magnitude (m):
- 3.30
- Size:
- 1° ' 20'
- Right Ascension:
- 17h 53.8m
- Declination:
- -34° 47'
- Constellation:
- Scorpius
- Messier #:
- M7
* One can see up to magnitude 7-8 objects with perfect eyes under ideal dark sky conditions.
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