M8, the Lagoon Nebula, below center, is an amazing emission nebula and stellar nursery in Sagittarius.

M20, the Trifid Nebula, is another remarkable object, seen at the top right of the frame. It is a complex of red emission and blue reflection nebulosity intersected by three dark lanes, from which the Trifid gets its name.

M21 is a rich open cluster located 1/2 degree to the northeast of M20.

M20 and M21 are also believed to be 5,000 light-years distant.

The nebula complex NGC 6559 is to the east of M8 (left in this image), and contains dark nebulae B91 and B303, as well as bright nebulae IC 4684, 4685 and IC 1274/5.

Below M8 to the southeast at the bottom edge of the frame is globular cluster NGC 6544.

M8 was discovered by Giovanni Battista Hodierna before 1654. M20 and M21 were discovered by Charles Messier in 1764.

North is to the top in the above image.

M8, M20, M21 Catalogs: M8: NGC 6523 M20: NGC 6514 M21: NGC 6531 Common Name: Lagoon, Trifid Object Type: M8: Emission Nebula M20: Reflection and Emission Nebula M21: Open Cluster Magnitude: M8: 5b M20: 6.3v M21: 5.9v Size: M8: 60' x 30' M20: 20' M21: 16' Constellation: Sagittarius Image Field Centered At: RA: 18h 05m 24s Dec: -23° 41' 33" Individual object coordinates can be found in the Master List.