Camera: Starlight Xpress SXVF-H16 with FLI CFW-2-7 Filter Wheel

Mount: Losmandy G-11/Gemini

Scope: Astro Systemme Austria N8 Astrograph

Colors: Ha:L:R:G:B

Exposure Time: 340:35:35:35:35 minutes

Post-Production: MaxIm DL and Photoshop CS3

The Horsehead Nebula is one of the most famous nebulae on the sky. It is visible as the dark indentation to the red emission nebula seen just right of center in the this photograph. The brightest star is Alnitak, the left star in the belt of the familiar constellation Orion. The horse-head feature is dark because it is really an opaque dust cloud that lies in front of the bright red emission nebula. Like clouds in Earth's atmosphere, this cosmic cloud has assumed a recognizable shape by chance. After many thousands of years, the internal motions of the cloud will alter its appearance. The emission nebula's red color is caused by electrons recombining with protons to form hydrogen atoms. Also visible in the picture are blue reflection nebulae that preferentially reflect the blue light from nearby stars. (Text description from APOD)