M52 and NGC 7635 – Open Cluster and Bubble Nebula

Open Cluster, M52, discovered by Charles Messier in 1774, can be found in a rich field of the Milky Way. M52 has been dubbed the name “salt and pepper” cluster. The distance to the cluster is not very well known, but estimates anywhere from 3,000 light years to 7,000 light years, but the Sky Catalogue 2000.0 gives it a distance of 5,200 light years. Estimates are complicated due to higher interstellar absorption the light suffered during its travels toward Earth. Using 5,000 light years as an average the clusters diameter is estimated to be around 13 arc minutes corresponding to a diameter of 19 light years.

The Bubble Nebula, NGC 7635, discovered by William Herschel in 1787, lies in close proximity to the open cluster, M52. The bubble formed from stellar winds from the massively hot central star (SAO 20575 or BD+60°2522) at an 8th magnitude. The nebula itself has an estimated distance of 11,000 light years away with an apparent magnitude of ~10, and a diameter of 15 x 8 arc minutes.

Location of M52 and NGC 7635.

Location of M52 and NGC 7635.

Through the eyepiece from a nice dark location it is easy to make out M52 just fine and count many of the main stars within the cluster without the use of averted vision. The bubble nebula is a little more of a challenge. When I imaged the picture below there was an 88% moon which made it impossible for me to find NGC 7635.

M52 and NGC 7635 – Open Cluster and Bubble Nebula. 08-17-13

This image is 65 x 120 sec light frames, 33 dark frames, 33 flat frames, and 43 bias frames. Taken on the night of August 17, 2013 with an 88% moon washing out a lot of the sky. Image stacked in Deep Sky Stacker and post processing in Photoshop. There were some major editing I had to do in order to clear out noise created from thin clouds on occasion, and the light of the moon making my illumination a bit uneven.

All my Messier Object information from: The Messier Catalog. Screen shot of object location taken in Stellarium. Image stacking in Deep Sky Stacker.

Equipment:
Omni XLT 150 with CG-4 mount
Modded Canon 350D
T-ring and adapter
Intervalometer
Polar Scope for alignment

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