Bubble and Cluster

The Bubble Nebula, NGC7635, part of a larger HII could, Sh2-162, in the constellation Cassiopeia with the open cluster M52 in its neighbourhood (top left corner of the image). The “bubble” is produced by the stellar winds from a massive young and hot star, SAO20575, in its center. The bubble is embedded in a giant molecular cloud that contains the expansion of the bubble nebula while itself being excited by the hot central star, causing it to emit light.

This image is a two-color narrowband composite using a total of 6 hours of Ha and OIII data. For a more natural appearance the stars are from a small set of RGB exposures.