NGC 7635, also known as the Bubble Nebula, or Caldwell 11, is a HII region emission nebula in the constellation Cassiopeia.
The nebula lies at a distance of 7,100 to 11,000 light years from Earth.
The Bubble Nebula was created about 300,000 years ago, when stellar wind from the massive hot (8.7 magnitude) young central star, SAO 20575, expelled a shell of dust and gas. The expelled material rapidly moved away from the star and, as it interacted with the nearby molecular cloud, it began to create the nebula’s bubble shape.
Data captured over 6 nights between 21st October & 11th November, 2018.
28x 10 minute exposures with Ha filter.
63x 10 minute exposures with Oiii filter.
62x 10 minute exposures with Sii filter.
Total Exposure 25.5 hours.
Skywatcher Quattro 200 CF
Atik 428EX Mono
This image was processed in Pixinsight & Lightroom.
Calibration and Registration using Batch PreProcessing script.
Dynamic Crop - Cropped to remove any black edges.
Dynamic Background Extraction - Applied to remove background gradients. (Each Channel Separately)
Deconvolution - To bring out some fine detail & tighten stars, 50 iterations. (Each Channel Separately)
Multiscale Linear Transform - Noise reduction.
SHO-AIP Script - To create the SHO image.
Histrogram Transformation - To stretch the image and bring out the data.
UnsharpMask - To sharpen detail in core, with sharpening mask in place to target nebulosity.
Dark Structure Enhance Script - Result blended 50-50 with original.
SCNR - To remove green and bring out Blue & Gold.
Export as JPEG and import into Lightroom.
Increase contrast (+15)
Reduce Shadows (-75)
Reduce Blacks (-25)
Increase Vibrance (+25)
Increase Yellow Saturation (+100)
Increase Blue Saturation (+40)
Decrease Magenta Saturation (-100)
Noise Reduction Luminance (25)
Export final JPEG for upload.