Took a while to get this one done. This data is actually all red and infrared and mapped in a way that the shorter wavelengths are blue so it's representative or false color--however you want to word that.

The blue outer shell is a very faint structure which barely shows up above the noise. I went ahead and used Photoshop's noise reduction filter and a median filter on it. The median filter in particular is destructive and I haven't ever used it on any Hubble images before. I decided since the shells were barely there anyway there wasn't much to destroy.

The nebula itself is <a href="http://en.wikipedia.org/wiki/Calabash_Nebula" rel="nofollow">pretty neat</a>. It's also called the Rotten Egg because of its sulfur content. You don't want to sniff it.

Red: hst_11580_08_wfc3_ir_f167n Green: hst_11580_08_wfc3_ir_f110w Blue: hst_08326_51_wfpc2_f791w_wf Blue-green screen layer for the blue shells: hst_08326_50_wfpc2_f656n_wf