Wouter's Astro-photography

NGC7635 The bubble nebula


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)

Image data

Exposure: 36x300s

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

Fitsconversion: Fitsliberator

image processing: Adobe Photoshop CS5



Object data



Caldwell 11

The Bubble nebula


Constellation: Cassiopeia


Type: Emission nebula



RA: 13h 12m

Dec: +61° 12'


Dimensions: 15' x 8.0' (bubble 3'x3')


Magnitude: 10


Distance: 7100 lightyears


Discovered by William Herschel in 1787


© Wouter D'hoye 2016 - Last update February 1st 2015