Keyhole Nebula

At the heart of the southern Great Eta Carina Nebula (NGC 3372) is the Keyhole Nebula (NGC 3324), showcasing the famous star, Eta Carina, to the lower left. Unfortunately, most denizens of the Northern Hemisphere have never glimpsed this bright region. In this version, taken from Chile, we present a narrowband image made up of only 2 frequency components -- Ha (656.3 nm) and OIII (500.7 nm), represented by the red and blue in the image, respectively -- the green channel was synthesized from the other 2 using Steve Cannistra's modified bicolor technique in Adobe PS.