NGC 2244 is an open cluster in Monoceros surrounded by
nebulosity, NGC 2237, the Rosette Nebula.
Hover over the picture for an annotated version
Date: 2 and 16 October 2025
FOV: approximately 2° 27' × 1° 38' NGC 2237 is about 1.3°
Telescope: Stellarvue SVX102T + SFFR.74 reducer/flattener
(522.29mm, nominally 528mm, f/5.18)
Guiding: ZWO ASI120MM mini mono guide camera,
Stellarvue F050G 50mm guide scope
Computer: ASIair pro Raspberry Pi
Mount: ZWO AM5N
Camera: ZWO ASI071MC Pro Cooled (-10°C) Color CMOS
Pixel size: 4.78 μm
Resolution: 1.888 arcsec/pixel
Filter: Optolong L-eNhance 2 Oct and Optolong UV/IR cut 16 Oct
Frames:2 Oct 202529 × 300 seconds × 90 gain,
16 Oct 202555 × 300 seconds × 90 gain
Stacking: eighty-four 300 second frames using PixInsight
Calibration frames: 20 dark, 20 flat, 20 dark flat per session
Total Time: 7 hours
Processing: Pixinsight
SPCC, DBE, SPCC, BlurXT, NoiseXT → Linear_UVIR
Linear_UVIR HTS, GHS, MStr,
PixelMath MStr + GHS + HST → Stars_UVIR
Linear_UVIR StarXT → Starless_Oct16
HTS, GHS, MStr,
PixelMath MStr + GHS + HST → Starless_UVIR
SPCC, DBE, SPCC, BlurXT, NoiseXT → Linear_LeNh
Linear_LeNh StarXT → Starless_Oct2
HTS, GHS, MStr,
PixelMath MStr + GHS + HST → Starless_LeNh
PixelMath ~(~Starless_UVIR*~Starless_LeNh) → Starless
PixelMath ~(~Stars_UVIR*~Starless) → Final Image
Location: Darling Hill Observatory near Vesper, NY
