NGC 7139, is a moderate sized planetary nebula in Cepheus.
Hover over the picture for an annotated version
Date: 6 September 2026
FOV: 10' × 6' 40", HGC 7139 is about 1.4' x 1.2'
Rotation: 0.006°
Telescopes: Celestron 9.25" EdgeHD SCT (nominally 2350mm, f/10
with Celestron 0.7 × reducer, 1679.18mm, f/7) and a
SVBony MK127 Mak-Cass (nominally 1500mm, f/11.8
calculated 1422.25mm, f/11.2)
Guiding: ZWO ASI120MM mini mono guide cameras,
SVBony SV165 Mini 40mm f/4 guide scopes
Computer: ASIair plus and ASIair 256G
Mounts: ZWO AM7 and AM5 harmonic drives
Cameras: ZWO ASI6200mc 100 gain and ASI071mc 90 gain (-10°C)
Pixel size: 3.76 μm and 4.78 μm, respectively
Resolution: 0.462 (C925) and 0.693 (MK127) arcsec/pixel
Frames: 84 × 300 seconds, Optolong L-eNhance filter (C925)
87 × 300 seconds, Optolong UV/IR cut filter (MK127)
Total Time: 14 hours 15 minutes
Processing: Pixinsight
preprocessing → L-eNh×84 and UV/IR×87
L-eNh: MGC, DBE, SPCC, BXT, NXT, StarXT → LinearLeNh
UV/IR: MGC, DBE, SPCC, BXT, NXT → LinearUVIR
LinearUVIR: StarXT → LinearUVIR_StarXT
LinearUVIR: MultiAdaptiveStretch → Stars
PixelMath ~(~LinearLeNh*~LinearUVIR_StarXT) →
LinearStarless, HTS, GHS, MStr, MAS,
PixelMath 0.25*(HTS + GHS + MStr + MAS) → Starless
PixelMath ~(~Stars*~Starless), DynCrop/Scale
Location: Darling Hill Observatory near Vesper, NY
