M18 · open cluster
Messier 18
Messier 18 or M18, also designated NGC 6613 and sometimes known as the Black Swan Cluster, is an open cluster of stars in the constellation Sagittarius.
Image: Fabian Rodriguez Frustaglia. CC BY-SA 4.0, via Wikimedia Commons.
Identity & coordinates
Identification
- Primary designation
- M18
- All designations
- M18 · NGC 6613
- Object type
- Open Cluster
- Constellation
- Sagittarius
- Best viewing
- Summer
Coordinates & physical
- Right ascension (J2000)
- 18h 19m 58s
- Declination (J2000)
- −17° 06' 07"
- Apparent magnitude (V)
- —
- Distance
- —
Visibility tonight
The science
Messier 18 or M18, also designated NGC 6613 and sometimes known as the Black Swan Cluster, is an open cluster of stars in the constellation Sagittarius. It was discovered by Charles Messier in 1764 and included in his list of comet-like objects. From the perspective of Earth, M18 is situated between the Omega Nebula (M17) and the Small Sagittarius Star Cloud (M24).
Summary adapted from Wikipedia · CC-BY-SA-4.0
References
- SIMBAD Not resolved
- NED Fetched May 8, 2026 View in NED ↗
- Wikipedia Fetched May 8, 2026 Read full article ↗
Wikipedia title resolved via designation — fell back to an alternate catalog designation.
1 merge conflict resolved
- coordinates: SIMBAD missing → NED used