After an abysmal winter and spring season here in Northern Germany, I was finally able to finish a new project. Inspired by the amazing image of vdB 130 & Barnard 344 by Yannick Akar, I tried to capture some data for the target with my C14 Hyperstar & ZWO ASI 1600 MM Pro. Notice, that the Ha and SII data was captured during midnight twilight at the end of May and first half of June 2023. From my Bortle 4 location at 54° north, the sky was still a little bit darker than a typical full moon night. Seeing on some of these nights was very good. On the downside, the nautical twilight nights are becoming quite short ~ 2 h, so collecting larger amounts of data becomes quite cumbersome.

Equipment

ZWO ASI 1600 MM Pro @ -20°C
+ C14 & Starizona Hyperstar v2 @ 675 mm (f/1.9)
+ Baader 2" Highspeed Narrowband SHO filters (old version)
+ Celestron EF
+ Tempest Cooler
+ Omegon Dew Heater
+ Astrozap Dew Shield for C 14 Hyperstar
on CGE-Pro mount

Cable managment to mitigate Hyperstar diffraction spikes.

Autoguiding:
Artesky 70 mm Guidscope (f=400 mm)
ZWO ASI 120 MM mini
PhD2 (Multistarguiding)
Dither every 4 subs

light frames:
485 x 60 s (Ha, gain=139, offset=21)
418 x 60 s (SII, gain=139, offset=21)
107 x 60 s (OIII, gain=139, offset=21)

dark frames:
60 x 60 s

acquired with N.I.N.A.

Remaining Issues
- more OIII data is required to improve s/n ratio, however OIII features are quite diffuse, so higher s/n might be not as important than for the Ha and SII channel
- quite large halos in the OIII data, especially noticeable in the vicinity of the bright, red star at the top of the image, need to replace the filter.
- have to capture some RGB stars.

Post-Processing:

PixInsight

Processing based in parts on the excellent HSHO tutorial https://youtu.be/UzL_UwcqkfI by @cuivlazygeek

Ha, OIII, SII channel:
automatic rejection of subs with the subframe selector based on number of stars, FWHM and eccentricity, manual rejection of bad subs, image calibration (dark frames only) & image registration with WBPP script, NSG script, image integration, dynamic crop, DBE, BXT, Darkarchons EZ Processing Suite: EZ Softstretch

HSHO combination via LRGBCombination with 100% weight on all channels and chrominance noise reduction, remove magenta tints in the color image by image inversion and SCNR, star extraction using SXT

Starless HSHO processing:
Contrast & color saturation enhancements of the nebula by curves transformations, noise suppression using NXT, Dark Structure Enhance script, export starless image as tiff

Adobe Lightroom 6:
Further contrast, level tweaks and most importantly HSL settings to enhance the orange and red colors
Hue: Orange -54, Yellow -43
Saturation: Red +17, Orange -17, Yellow +30, Aquamarine +16, Blue +5
export tiff

PixInsight
Import Lightroom tiff file, add stars to starless image with Pixelmath, apply star mask, enhance color saturation of stars

Location (Bortle 4): Schwentinental, Germany

- CS Daniel