Westerlund 1 is the small and strangely red cluster of stars near the upper edge of this image.
Located in the southern constellation Ara and about 8500 light years from earth, this cluster is
home to some of the largest stars in our galaxy. It contains at least 4 blue supergiant stars, 2
blue hypergiants, 6 yellow hypergiants, 4 red supergiants, and 24 Wolf-Rayet stars. The cluster
appears so strikingly red because of the high absorption of interstellar light between the cluster
and earth.

Visually more interesting are the dark lanes of gas and dust that occupy the middle of this image,
and the very faint red emission nebula at the lower left, neither of which (as far as I can tell)
have been given a catchy name or even a number in a list.

Image data:

Camera: STXL-11002
Telescope: Planewave 17" CDK
Exposure: LRGB and Ha, total exposure = 13 hours 55 minutes
Location: Observatorio El Sauce, Chile