NGC 7635, also called the Bubble Nebula, Sharpless 162, or Caldwell 11, is a H II region emission nebula in the constellation Cassiopeia. It lies close to the direction of the open cluster Messier 52. The "bubble" is created by the stellar wind from a massive hot, 8.7 magnitude young central star. The nebula is near a giant molecular cloud which contains the expansion of the bubble nebula while itself being excited by the hot central star, causing it to glow. It was discovered in 1787 by William Herschel. The star SAO 20575 or BD+602522 is thought to have a mass of 10-40 Solar masses.

With an 8 or 10-inch (250 mm) telescope, the nebula is visible as an extremely faint and large shell around the star. The nearby 7th magnitude star on the west hinders observation, but one can view the nebula using averted vision. Using a 16 to 18-inch (460 mm) scope, one can see that the faint nebula is irregular, being elongated in the north south direction.[Source Wikipedia]

The image was captured with the Meade 12"LX200, using the Atik 383L+ mono at F7.16 (i.e. 2182mm FL). Astronomik's Ha narrow band filter was used for the luminance. All subs were taken at 1x1 bin, -10C, and 10 minutes each.

IMAGE A:

Ha : 10 subs (1.67 hr) on Aug 28th.

Processing was done with PixInsight, using the minimum amout of steps.

North is up. This is a very slight crop.

IMAGE B:

Ha : 10 subs (1.67 hr) on Aug 28th.

Red: 6 subs (1.00 hr) on Aug 30th.

Green: 6 subs (1.00 hr) on Aug 30th.

Blue: 6 subs (1.00 hr) on Aug 30th.

Processing was done with PixInsight, following (for the most part) kayronjm's tutorial of Feb. 24th

North is up. This is a medium crop due to my inability to find the original guide star from Ha to the RGB subs. North is up.

I recognize that there is a bit of gradient from left to right. This was introduced by the RGB contribution. I may go back and try to gather more RGB and eliminate this gradient.

Below is an additional hour of R,G and B.

IMAGE D :

Ha : 10 subs (1.67 hr) on Aug 28th.

Red: 12 subs (2.00 hr) on Aug 30th.

Green: 12 subs (2;00 hr) on Aug 30th.

Blue: 12 subs (2.00 hr) on Aug 30th.