About NGC 6531 (M21)

NGC 6531 is a rewarding deep-sky target and presents itself as a diffuse object. It has moderate brightness.

Current visibility

It is currently below the horizon.

It stays above 30° for roughly 8 hours.

Observing conditions matter, fine detail requires darker skies.

Observing tips

This object is better suited for experienced observers.

What to expect

It appears more compact than typical clusters.

Type

Open Cluster

Constellation

Sagittarius

Distance

4250 ly

Size

13.0'

Season

Summer

Difficulty

Moderate

Magnitude

6.5