NGC 7635 is a very faint nebula complex just southwest of the open cluster M52. It's a very tough target to observe visually. But in long exposure images it's a really splendid sight. The nebula is best known for the bubble that is part of NGC7635. Contrary to what many people would think the bubble is not a planetary nebula. Instead it's a cavity that is blown in the nebula by radiiation pressure form the 9th magintude star SAO20575, the bright star in the brighter portion of the bubble.
The nebula was discovered by William herschel in 1787, who described it as being a star of 9h magniude surrounded wih very fain enbulosity.
The image above as taken at my observatory at home in Belgium. (click on the image for a larger version)
Filters: Baader UHC-S
Camera temperature: -30°C
Date: October 30th 2013
Location: Zele, Belgium
Camera: SBIG ST2000XM
Telescope: Skywatcher MN190
Mount: Software Bisque Paramount MX
Image aquisition: The Sky X
Preprocessing: Deep sky stacker
image processing: Adobe Photoshop CS5
The Bubble nebula
Type: Emission nebula
RA: 13h 12m
Dec: +61° 12'
Dimensions: 15' x 8.0' (bubble 3'x3')
Distance: 7100 lightyears
Discovered by William Herschel in 1787
© Wouter D'hoye 2016 - Last update February 1st 2015