NGC 7635 – The Bubble Nebula in Cassiopeia

Telescope: Meade SN8 at f/4, Orion Atlas EQ-G
Camera: ZWO ASI071MC, Highpoint Scientific UV/IR filter
Sensor Temperature: 0C, Gain: 200, Offset: 50
Guide scope: Williams Optics 50mm, Meade DSI Pro II, PHD
Exposure: 135x120sec saved as FITS
Darks: 32x120sec saved as FITS
Flats: 32x5sec, LED tracing tablet
Average Light Pollution: Red zone, good transparency
Lensed Sky Quality Meter: 18.6 mag/arc-sec^2
Stacking: Mean with a 2-sigma clip.
White Balance: Nebulosity Automatic
Software: Nebulosity, Deep Sky Stacker, Photoshop

This is NGC 7635, the Bubble Nebula in Cassiopeia (the Queen). This is almost the inverse of a planetary nebula. Planetaries are expanding shells of gas shed from a dying star. The Bubble is formed from a hot blue star imbedded within a cloud of dust and gas. The intense radiation from the star has pushed out a sphere in the surrounding gas, making an empty bubble.

This is the first in a series of images that I am taking to explore the use of a simple UV/IR filter and adjusting the white balance as part of my processing in place of my usual Orion Imaging Skyglow filter. This first example is quite encouraging.

-John

NGC 7635 (7-24-2017)-2j.jpg