This image captures the area of sky around the super cluster - Westerlund 1. It is located in the Milk Way in Ara near the tail of Scorpius and close the constellation of Norma. The cluster, and surrounding area, is quite red due to atmospheric absorption caused by interstellar dust.
The image makes for nice viewing with the scattering of Ha regions and the distinctive dark nebula running across the image. The dark nebula kind of looks like a sea horse dance across the field of stars. I couldn't find any separate catalogue reference to this dark nebula (at least in Stellarium anyway!) so it may not be cataloged as such.
Link to image on Astrobin here.
Click on image in Astrobin for a larger view.
Clear skies,
Rodney.