Messier 23
Star cluster in Sagittarius · 2,150 light-years
🔭 Explore Messier 23 in the 3D map →View Messier 23 images →| Type | Star cluster |
|---|---|
| Constellation | Sagittarius |
| Right ascension | 17h 57m 05s |
| Declination | −18° 59′ |
| Object distance | 2,150 light-years |
| Apparent magnitude | 5.5 |
| Apparent size | 16.8′ (arc-minutes) |
| Approx. true diameter | 10.5 light-years across |
| Also known as | M23 · NGC 6494 |
Messier 23 is a star cluster (also catalogued as NGC 6494) in Sagittarius — a gravitationally bound family of stars sharing a common origin. It was recorded by Charles Messier in his famous catalogue of 110 deep-sky objects. It spans roughly 16.8 arc-minutes on the sky. At about magnitude 5.5, it is an easy target for binoculars and small telescopes.
Although it appears about 16.8′ wide on the sky, its real span is roughly 10.5 light-years — the difference is a measure of how far away it lies.
Observing Messier 23
Messier 23 lies in the constellation Sagittarius and is best placed in the evening sky around June. Its maximum altitude above the horizon depends on your latitude. Lying near the celestial equator, it can be seen from both hemispheres. It is a comfortable target for binoculars and small telescopes.
See Messier 23 in Universe Finder
Open the interactive 3D map to fly to Messier 23 and see it in context among the real stars around it. Launch the 3D view →
Sources
- Position, magnitude and angular size from the OpenNGC catalogue (Mattia Verga).
- Object identity cross-referenced with SIMBAD (CDS, Strasbourg).
- Image credits and the original observation source are linked with each photograph.
Related objects
- Pleiades — star cluster
- Hercules Cluster — star cluster
- Small Sgr Star Cloud — star cluster
- Messier 25 — star cluster
- Messier 103 — star cluster