NGC 7635 - Bubble Nebula

The bubble is on the top-right of the image. It  is in the constellation Cassiopea. Its designation in the New General Catalogue is NGC 7635. It is HII region, i.e. a region of ionized hydrogen. The bubble itself is formed by the strong stellar wind of a young massive star.

On the lower-left, the bright red nebula, another HII region, is NGC 7538. And the small star cluster at the bottom is NGC 7510. Their are in the constellation Cepheus.

50 exposures of 5 minutes.
Camera : Canon EOS 1000D unfiltered
Telescope : Takahashi FSQ-106ED refractor
Mount : Takahashi EM-200
Guiding : Orion Starshoot Autoguider on a William Optic Zenithstar 66SD refractor.
Outside temperature : 4°C to 6°C
Sensor temperature : 15°C ot 17°C
Humidity : 45%
SQM : 21.5
Software : auto-guiding with PHD2, acquisition with Astro Photography Tool, processing with PixInsight.
Location : Gresse-en-Vercors, France