Messier 4
Star cluster in Scorpius · 7,200 light-years
🔭 Explore Messier 4 in the 3D map →View Messier 4 images →| Type | Star cluster |
|---|---|
| Constellation | Scorpius |
| Right ascension | 16h 23m 35s |
| Declination | −26° 32′ |
| Object distance | 7,200 light-years |
| Apparent magnitude | 5.4 |
| Apparent size | 28.2′ (arc-minutes) |
| Approx. true diameter | 59.1 light-years across |
| Also known as | M4 · NGC 6121 |
Messier 4 is a star cluster (also catalogued as NGC 6121) in Scorpius — 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 28.2 arc-minutes on the sky. At about magnitude 5.4, it is bright enough to glimpse with the unaided eye under a dark sky.
Although it appears about 28.2′ wide on the sky, its real span is roughly 59.1 light-years — the difference is a measure of how far away it lies.
Observing Messier 4
Messier 4 lies in the constellation Scorpius and is best placed in the evening sky around May. Its maximum altitude above the horizon depends on your latitude. It is best placed for observers in the southern hemisphere, and sits low for those far north. At its brightness it can be found with the unaided eye under a dark sky and is easy in binoculars.
See Messier 4 in Universe Finder
Open the interactive 3D map to fly to Messier 4 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