OBJECT DATA: NGC 7635 (Cassiopeia). Distance: 15.000 light years. Angular size: 15' X 8'
CATEGORY: Emission nebula
OPTICS: Takahashi FSQ f/5
MOUNT: Losmandy GM-8
CAMERA: Modified Canon 350D (with Baader IR filter) @ 800 ISO
FILTERS: Baader 7 nm H alpha filter
DATE: October 1 and 3, 2008
LOCATION & CONDITIONS: Atienza Observatory (Las Rozas) - Madrid. 19 ºC and 12 ºC
EXPOSURE: 30 X 900 sec. (Total: 7.5 hrs.)
CALIBRATION FRAMES: 12 darks, 20 flats
AQUISITION & PROCESSING: MaxIm DL, Images Plus, Photoshop CS3
COMMENTS: NGC 7635 is a H II region emission nebula. It lies close to the open cluster Messier 52 (visible at bottom left). 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.