Oregon Star Party, Ochoco National Forest, July 17 – 20, 2023

Cepheus is rich in deep sky objects, especially dark and reflection nebulae.  With excellent dark skies at the Oregon Star Party, it was a good second or all night target.  Over four nights, I collected about 11 hours of usable data, limited only by the light of dawn.  Inspired by several beautiful images on Astrobin, I gave this region a try using Red, Green, Blue and Hydrogen-alpha filters.  This turned out to be a processing challenge, especially with bloated bright stars and continuing confusion on how to best add Ha to the Red channel or the broadband filters RGB color image.  StarXTerminator failed to remove the large and bright stars in linear or stretched states. So, I bumbled my way through many experiments in PixInsight to arrive at this not so satisfying image.

This image in Cepheus has a nice variety of objects.  The reflection nebula from van den Bergh’s catalog, vdB 152, is a part of the large molecular cloud, the dark nebula LDN 1219.  To some imaginative astronomers who are fans of the original Star Trek series, this resembles the “Doomsday Machine.”  The hydrogen-alpha filter brought out two additional objects.  The red filaments are part of a large supernova remnant, SNR G110.3+11.3.  The red region at the top of the frame is a planetary nebula, PK111+11.1.  The blue in the nebula was overwhelmed by the Ha red during PixInsight processing.

Imaging details:

Stellarvue SVX102T refractor with 0.74x focal reducer (FL = 528mm, f/5.2)
ZWO large off-axis guider with a ZWO ASI 174MM mini guide camera
Losmandy G11 mount with Gemini 2
ZWO ASI 2600MM Pro cooled monochrome camera (-5C)
Chroma 36mm Luminance, Red, Green, and Blue filters
Equatorial camera rotation: 90 degrees

Software:    Sequence Generator Pro, ASTAP plate solving, PHD2 guiding, 
    Losmandy Gemini ASCOM mount control and web client interface,
    SharpCap Pro for polar alignment with a Polemaster camera,
    PixInsight 1.8.9-1,
    Photoshop 2023

Hydrogen-a  10 min x 27 subframes (270 min), Gain 100, Offset 32, 1x1 binning
Red             4 min x 33 subframes (132 min), Gain 100, Offset 32, 1x1 binning
Green          4 min x 32 subframes (128 min), Gain 100, Offset 32, 1x1 binning
Blue            4 min x 32 subframes (128 min), Gain 100, Offset 32, 1x1 binning