Messier 21
M21 · NGC 6531
👁️ Naked-eye
📋 A written introduction is coming — for now this page shows official values only.
Object
- Type (NASA)
- OC
- Apparent magnitude
- 5.9 mag
- Apparent size
- 13 ′
Source:NASA HEASARC (Goddard Space Flight Center) · checked 2026-11-02 ↗
Related
Constellation
In everyday life
- At magnitude 5.9 it is bright enough for the naked eye (limit about 6) — look from somewhere dark.
- It spans about 13′ of sky — about half the full Moon's 31′.
- It lies in Sagittarius — find the constellation first to know where to look.
Worked out from this object's official values.