The Horsehead (IC 434)

Images taken: March 2014, by Thomas Moorman, Zac Creel.

Telescope: CDK 17-in at f/4.6. Camera: SBIG ST-10 CCD.

Exposures: 2 x 20 min red, green, blue; 1 x 60 min with H-alpha filters (total 3 hours).

Measured surface brightness of the bright nebula: 22.2 mg/as^2.

The Horsehead is a dark interstellar dust cloud that blocks the light of the red glowing gas behind it. It is quite difficult to image because of it very low surface brightness (S/B=1:4.5).

Image processing: CCDoops + CCDsoft + Photoshop CS.