M 21 NGC 6531 Webb’s Cross

Capture

Seestar s50 91 stacks

Date

7 June 2026

Location

Camden, NSW

Original

1080 × 1920 px

M 21 NGC 6531 Webb’s Cross is an open cluster of stars located to the north-east of Sagittarius in the night sky, close to the Messier object M20. M21 consists mainly of small, faint stars, but is also home to a few blue giants. The cluster contains about 57 confirmed members, among which are about 35 stars with a visual magnitude between 8 and 12. At a distance of 4,250 light years from Earth and approximately 20 light years in diameter, this group started life together about 4.6 million years ago. M21 is not visible to the naked eye, however, with the smallest binoculars it can be easily spotted on a dark night. Apparent magnitude 6.5.

See it in the star clusters gallery