NGC 7635: A New O-Type Star Does Its Thing
A.K.A: Sh2-162, Caldwell 11, Bubble Nebula

Several alternative (starred and zoom) images are availabe at the rigth.

OTA: A.G. Optical iDK20
Camera: Morovian 61000 Pro
Observatory: Insight Observatory (AFIL-7, Spain)
Date of Capture: Oct, '23
Date of Processing: Nov, '23

Exposures:
R: 10 x 600 sec
G: 10 x 600
B: 10 x 600
L: 15 x 600
H: 22 x 600 sec
O: 22 x 600
S: 22 x 600
Total Exposure time: 18.5 hours

Processing Tools:
1.    Commercial: PixInsight, Topaz (Studio2, Photo AI2), Photo Director 365
2.    Pixinsight Addons: NoiseXTerminator, StarXTerminator
3.    My Scripts: NB_Assistant, AC_Restar, Subframe Weighting Tool (Excel w/ J. Hunt), ColorTweaker

Target Description:
Two nebulae occur in this image. The "bubble" is caused by excited gasses being blown from around an O-type star that recently ignited. That star is the brightest one within the boundaries of the bubble. The outer cloud is described as a gigantic molecular cloud (Wikipedia). The regions of that cloud that lie proximal to the young star and the bubble are illuminated by that star. Along the inner margin of that GMC, we observe inward-pointing cone-like structures and bright edges of gas and dust. Apparently, these form from the outward pressure pushing back the GMC, but where the cloud is most dense, those regions offer more resistance to the pressure and, at those small areas, form bright-edged, pointed cones. Their brightness probably arises from compression or shock-front interactions with the outward flow of gas and dust.

Processing Description:
This image portrays the true-color mapping of the narrowband images after subtracting continuum emissions, leaving only the pure emission lines. Doing this and augmenting the image with the L channel in a rigorous fashion that did not distort colors required many processing steps and resulted in many tangled and swollen neurons by the time it was over.

Ultimately, two images were generated. This one, as described above, and another one where This image was combined with the narrowband extracted lines…of course, that one had a different color scheme. I did not process that second image to completion; I became a fan of this pure emission-line image.

Statistics:
Image Radius: 0.36 deg
Distance: 11,000 ly
Apparent Magnitude: 10
Average Surface Magnitude: 21
Pixel Span at Target: 16B km


Alex Woronow