SharpCap Forums

NGC 6888, the Crescent Nebula

This one was fun to process. I didn't do that much capturing and processing yet with the Optolong L-eXtreme filter, so it's all experimenting
It's just under 3 hours of data and really it needs more. But the weather here is SO bad, that I find this okay for now.

NGC 6888 is at around 5000 lightyears from Earth and is a emission nebula in Cygnus. It's caused by a Wolf-Rayet star which became a red giant around 320.000 years ago. Before that, it emitted stellar wind at a normal rate and speed. But when it became a red giant, the emitted stellar wind had a much higher speed and it overtook the stellar winds emitted earlier.
This is colliding with it and energizing it, forming the shell and 2 shockwaves: 1 outbound and 1 inbound. The inbound shockwave is creating so much energy and temperatures, that it is emitting X-rays.
And thus ends the lesson :p

Bortle 6/7
Meade LX200 8" f/10 ACF OTA
Ioptron CEM25EC montering (no guiding)
Optec Lepus 0.62X Standard reducer (0,73x effectively)
Optolong L-eXtreme filter
Zwo ASI071MC Pro camera

Captured with SharpCap Pro @ -10 Celsius / White balance R50 B50
17 x 600 sec / Gain 90 / Offset 20
30 x darks, 50x flats en 50x darkflats

Stacked with DeepSkyStacker
Processed with Siril and Photoshop
Siril: Crop, Horizontal Banding Reduction en Histogram
Photoshop: Levels, Camera Raw Filter (blacks, color saturation, clarity, sharpening, hue's), star reduction, Neat Image Noise Reduction, format to 1500px

Hi Menno, Quite dramatic-looking in that slightly more orange interpretation. My effort below looks rather greener and is more artificial since I boosted the O3/ HA ratio threefold in order to see more of it. How are you finding working with the reducer at F 7.0? Presumably - it is providing brighter images more quickly - is that how it seems?
Tim

Thanks Tim!
Yah, somehow this orange teint suited it best. Normally I am true to colors but this indeed looked kinda dramatic If I look at other captures, I see it from deep red till light pink.
Working with the reducer is okay. I don't notice any real dramatic effect when it comes to exposure times. I do have the feeling though that the OIII is more there because of it.
It's an idea to test it sometimes here with the same object: leave every setting the same, just captures with and without reducer.

Menno

Ooomph!!! That IS impressive!! Nice work!!
Greg

Thank you Greg

Menno