NGC 7635 - Bubble Nebula in Ha

NGC 7635, also called the Bubble Nebula and Sharpless 162, 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 15 ± 5 M☉[4] SAO 20575 (BD+60 2522).
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.

Telescope: APM Astrograph 107, f/6.5 with Baader Steeltrack Focuser and 2.5'' TS FF
Mount: HEQ5 Pro with EQ Mod and XBOX Wireless Controller
Camera: ATIK 314L+
Image Scale: 1.91 arcsec/pixel
Filter: Baader Ha 7nm
Guide Camera: QHY5 with PHD Guiding and TS UV/IR Block
Guide Scope: Skywatcher Finderscope 8x50
Exp. Time: 112 minutes, bin 1x1
Calibration Frames: no calibration frames
Capture: Nebulosity 2.3.0
Register, Stack: Maxim DL, CCD Stack
Processing: Photoshop CS3
Date: 17 Sep 2010
Location: Athens, GR

NGC 7635 - Bubble Nebula Wiki