Spiral Galaxy in Cepheus

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NGC6946: This is a very dim, 10th magnitude galaxy in Cepheus toward Cygnus, approximately ten million light years from Earth. Looking from the bright core outward along the spiral arms, the galaxy's colors show a change from the yellowish light of old stars in the galaxy's center to young blue star clusters and reddish star forming regions. NGC 6946 is also bright in infrared light and rich in gas and dust, exhibiting a high star birth and death rate. During the 20th century, at least six supernovae, the death explosions of massive stars, were discovered in NGC 6946. A small barred structure is just visible at the galaxy's core.


Technical Information:

LRGB: 360:150:150:150 (Luminance layer consists of 12 thirty-minute images, unbinned; R, G and B consist of 10 fifteen-minute images, all unbinned).

Equipment: 16" RCOS at about f/9, and an SBIG STL-11000M with internal filter wheel (Astrodon filter set), guided with an SBIG AOL, on a Bisque Paramount ME German Equatorial Mount.

Image Acquisition/Camera Control: Maxim DL, controlled with ACP and TheSky.

Processing: All images calibrated (darks and dawn flats), aligned, sigma reject performed, and combined in CCDStack. Luminance layer deconvolved in CCDStack. Color combine in Photoshop. Finish work (curves and levels, increasing saturation, smart sharpen and selective Gaussian blurs on luminance layer) was done in Photoshop CS2.

Location: Data acquired remotely from the Tejas Observatory, located on the grounds of New Mexico Skies, near Mayhill, NM (elevation 7300 feet).

Date: Images taken in late September and early October, 2008. Image posted October 28, 2008.

CCD Chip Temperature: -20C

Seeing: Generally fair

Transparency: Generally good

Moon Phase: Little moon during imaging

Copyright 2008 Mark de Regt