Derby and District Astronomical Society

Caldwell 11 (NGC 7635)
The Bubble Nebula

Emission Nebula in Cassiopeia      RA 23h 20m 42s  Dec +61° 12m 00s

This image of NGC 7635 was captured by Peter Branson on the evening of August 28th 2021. The image was obtained by combining and processing 29 images each of 150s. The images were taken with a ZWO ASI224MC-Cool high frame rate camera through a Hutech IDAS light pollution filter and attached to a Celestron C9.25 Schmitt-Cassegrain telescope. The telescope arrangement was mounted on an NEQ6 mount. The camera suffers from amp-glow and sufficient 'darks' were taken to compensate for the amp-glow introduced in each image. The images were combined and processed in Nebulosity. Peter says - "I like coming back to familiar objects in the night sky and I really do like to revisit the Bubble Nebula in both wide-field and close-up settings. There's so much structure to be picked out in this nebula and each close-up reveals something new."   Image © Peter Branson.



This image of the Bubble Nebula was captured by Peter Branson and is made from two sets of images collected on August 8th and September 10th, 2015. The final image is made up from eight 60 second, fifteen 300 second and five 600 second exposures. The photos were taken with an ATIK 314L+ colour CCD camera attached to TS Photoline ED102 refractor telescope with field-flattener and Hutech IDAS light pollution filter attached. The telescope was guided using an Orion Mini autoguider controlled by PHD software. The images were stacked and further processed with 'curves' and 'levels' in Nebulosity.  Image © Peter Branson.



Adrian Brown captured this hydrogen-alpha photograph of The Bubble Nebula from imaging performed on the 14th, 15th and 16th of October 2011 using his Celestron 5" Schmidt-Cassegrain. The photograph is composed of 26 x 15 minute exposures. The telescope was focal reduced from f/10 to f/7 (approx 900mm focal length) and Adrian used his Atik ATK16HR CCD camera.  Image © Adrian Brown.



This image of the Bubble Nebula was produced by Adrian Brown (imaging) and Chris Newsome (image processing) in September 2007. The imaging telescope was an 80ED Refractor on a Celestron CGE mount with an ATIK 16HR camera and O-III and H-alpha filters. This setup was guided using a Skywatcher 80T refractor with an ATIK-2HS camera. The exposures were 16x10min binned 2x2 (2hr 40min) for the O-III, 4x10min binned 2x2 (40mins) for the H-alpha and 6x30min binned 1x1 (3hrs) also with H-alpha. Total exposure time was 6hrs 20mins. The O-III exposures were combined in Maxim DL with 20 bias and 20 flat exposures and all the exposures (O-III and H-alpha) had a DDP filter applied to them before combining. The resultant images were processed in CS2 with H-alpha being assigned to the red channel, O-III assigned to the blue channel and a synthetic green channel being created.  Image © Adrian Brown and Chris Newsome.



Adrian Brown produced the following image of the Bubble Nebula on the 15th July 2005. It is a monochrome image comprised of 9 x 6 minute exposures taken with an ATK-2HS camera through a Skywatcher EvoStar 80ED refractor. An Orion SkyGlow light pollution filter was also used. To help with tracking accuracy, he used a C11 SCT / ATK-1C camera combo as a guidescope along with a freeware program called GuideDog to auto-guide the mount. K3CCDTools was used to capture and stack the images and then final image processing was done in Maxim DL 4.11 and Photoshop 7.  Image © Adrian Brown.


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