M21 (NGC 6531)
| Typ: | Open cluster |
| Constellation: | Sagittarius |
| Size: | 13' |
| Distance: | 4.25 kLj |
| Brightness: | 6.5 mag |
| Position: | RA:18h 04.6m DEC:−22° 30′ |
| Max. height: | 17.50°, Jun. (midnight at +50°N) |
| Show in Stellarium | |
| Discovered: | Charles Messier, 1764 |
| Details: | Read more on Wikipedia |
Compared to its prominent neighbor M20, the Trifid Nebula, M21 is a somewhat plain open cluster. It is too dark to be visible by the naked eye and requires at least binoculars and a dark sky for visual observation.
The next image shows the full frame with the Trifid Nebular M20 in the center and a part of the Lagoon Nebula M8 on the right after a manual edit (580mm, ASI2600MM, LRGB 1h).
