M23 (NGC 6494)
Also known as M23 · M 23 · NGC 6494
M23 (NGC 6494) is an open star cluster in the constellation Sagittarius, about 2,250 light-years from Earth.
Facts
| Type | Open star cluster |
|---|---|
| Constellation | Sagittarius |
| Position (J2000) | 17h 57m 04s, −18° 59′ |
| Distance | 2,250 light-years (its light set off about 2,250 years ago) |
| Brightness | magnitude 5.5 (smaller is brighter; the faintest stars the eye sees are about 6) |
| Size on the sky | 35′ × 35′ (the full Moon is about 31′) |
| Filter | No filter (It shines in starlight of every colour, so a nebula filter would only dim it; a dark sky helps more.) |
| Studied in | 150 scientific papers (SIMBAD) |
When and how to see it
M23 (NGC 6494) is highest in the sky at midnight in June. From India (about 20° N) it climbs to about 51° above the horizon; from 50° N, to about 21°. To see it you need the naked eye from a dark site.
Heights are worked out for India and for 50° N. Set your location in Settings to see them for where you are.
For tonight's best time from your own town, the darkness and the Moon, open it on the map and see its "Tonight from your location" card.
More in Sagittarius
- Lagoon Nebula (M8)
- M18 (NGC 6613)
- M21 (NGC 6531)
- Omega Nebula (M17)
- Sagittarius A*
- Sagittarius Cluster (M22)
- Sagittarius Star Cloud (M24)
- Trifid Nebula (M20)
Everything in Sagittarius · All 88 constellations · All sky objects
Data: SIMBAD (CDS, Strasbourg; the site's weekly copy) · OpenNGC · Data sources & credits