Open star cluster · Sagittarius

Messier 21

M21 · NGC 6531

Above the horizon after darkHighest after dark 20:20 · southwest · 11°

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Where is Messier 21?

Times for LondonChange city

Look southwest, about 11° up at 20:20 in Sagittarius. It sinks lower through the evening and sets at 22:07.

From London tonight, Messier 21 is above the horizon after dark. It’s highest soon after dark, around 20:20, in the southwest at 11°.

At magnitude 5.9, with its light spread out, it needs binoculars and a dark sky.

This is position and timing only: clouds, haze and light pollution aren’t included.

From a very dark site, a faint hazy patch.

A scatter of stars; often the best view.

Many separate stars. Use your lowest magnification.

What you’re likely to see, not what a space telescope photographs. General guidance from catalog brightness and size, not a forecast for tonight.

Messier 21 (M21) is a open star cluster in Sagittarius, with a total brightness of magnitude 5.9 and an apparent size of 6.0′.

Sources: OpenNGC (CC BY-SA 4.0); star chart: Wikidata (CC0). Positions computed for your place and time with astronomy-engine. Data & Licences