The Bubble Nebula is a shell of gas surrounding a massive O star (BD+602522) which can be seen in the upper right quadrant of the bubble. The star is several hundred thousand times more luminous and around 45 times more massive than our Sun. A fierce stellar wind and intense radiation from the star ionizes the shell causing it to glow. The expansion of the bubble is contained by the surrounding giant molecular cloud. About six light-years in diameter, the Bubble Nebula is located in the direction of the constellation Cassiopeia.
As there was barely sufficient OIII data to produce a colour image, a false colour RGB image was created using the bicolour processing technique and then the Ha image was recombined as the luminance channel. This allows colour noise reduction, elimination of star halos and Gaussian smoothing prior to adding the Ha luminance layer. The final image was selectively smoothed, sharpened and colour enhanced using Photoshop and Color Efex Pro.
Right ascension: 23h 20m 45s | Declination: +61° 10' 31" | Distance: 11,000 Light Years
Field of view: 42 x 28 arcmin
Telescope: APM 152-1200ED F/7.9
Guiding: Starlight Xpress Active Optics SXV-LF-AO
Filters: Astrodon Ha (3nm), OIII (3nm)
Exposures: Ha 15 x 20 min, OIII 16 x 20 min
Total exposure: 10.3 hours
Image composition: Cannistra Modified Bicolour Narrowband Technique
Scale: 1.15 arcsec/pixel
Image acquired: Over 4 nights between 27th August – 18th September 2015
Image capture with MaxIm DL, FocusMax, ACP; Image processed with MaxIm DL; Photoshop CC 2014, Color Efex Pro.