17 Dec 2015

Ngc-6888, The Crescent Nebula

One of my "main" targets during last few months. First exposures was taken at the end of October so it took more than a month to finalize this one.

The Crescent Nebula (also known as NGC 6888, Caldwell 27, Sharpless 105) is an emission nebula in the constellation Cygnus, about 5000 light-years away. It was discovered by Friedrich Wilhelm Herschel in 1792.[2] It is formed by the fast stellar wind from the Wolf-Rayet star WR 136 (HD 192163) colliding with and energizing the slower moving wind ejected by the star when it became a red giant around 250,000 to 400,000[citation needed] years ago. (wikipedia)

This is a mag 7,4 object. Here's almost 8 hrs of data at HaRGB.

Ha = 3*1800" + 8*1200" (bin1*1)
R = 14*360" (bin2*2)
G = 11*360" (bin2*2)
B = 11*360" (bin2*2)

Full size on Astrobin

13 Dec 2015


NGC 891 (also known as Caldwell 23) is an edge-on unbarred spiral galaxy about 30 million light-years away in the constellation Andromeda. It was discovered by William Herschel on October 6, 1784. The galaxy is a member of the NGC 1023 group of galaxies in the Local Supercluster. It has an H II nucleus. (wikipedia)

Here's only color channels binned 2*2. This was a morning target for few of my imaging sessions so there's no luminance channel, yet. If the weather some day clears I've planned to continue with this one.

Only 2 hr 12 min of rgb here (42:60:30 bin2*2 all).