Bubble Nebula, NGC7635
Imaging: TS80 apo, ZWO ASI533 (100 gain, 0C), L-Enhance
Subs: 162x180s (8h), darks, flats, and darkflats
Software: NINA, Phd2, PixInsight
(Additional notes below)
The Bubble Nebula is an HII emission nebula in the Cassiopeia constellation. This is one nebula that is quite aptly named: the bubble is clear even on low quality images. According to Wikipedia, the bubble is created by the stellar wind from a massive hot young central star. The nebula is near a giant molecular cloud which contains the expansion of the bubble nebula while itself being excited by the hot star causing it to glow. With my framing here, the open star cluster Messier 52 can be seen in the lower left.
This object transits north from my location which is normally not viewable for me. Fortunately, the Bubble is quite high in the sky allowing a glimpse for about an hour each night. I took the photos for this image over 6 nights in late October and the start of November, for a total of 8 hours of images. As an emission nebula, it is basically all red in natural color. I prefer to use the HOO color palette which shows the difference between Ha and OIII gas with different colors.