LDN 1221, the Toast Nebula, and LBN 531
in the constellation Cepheus.
Hover over the image for an annotated view.
Date: 30 September – 2 October and 15 October 2025
FOV: approximately 4° × 2° 40'; LDN 1221 is about 10' across
Telescope: Askar FRA300 pro (300mm f/5 Petzval)
Guiding: ZWO ASI120MM mini mono guide camera,
SVBony SV165 Mini 40mm f/4 guide scope
Computer: ASIair pro Raspberry Pi
Mount: ZWO AM5N
Camera: ZWO ASI6200MC Pro Cooled (-10°C) Color CMOS
set to APS/c mode with gain 100
Pixel size: 3.76 μm
Resolution: 2.598 arcsec/pixel
Filter: Optolong UVIR cut 30 Sept – 1 Oct
Optolong L-Ultimate 1 – 2 Oct and 15 Oct
Frames: four sessions, all 300 second frames
UVIR cut: seventy-one frames 30 September to 1 October
fifty-two frames 26 October
L-Ultimate: sixty-nine frames 1 and 2 October
fifty three frames 15 October
Stacking: two hundred forty-five frames using PixInsight
Total Time: 20 hours 25 minutes
Calibration: 20 flats, 20 dark flats, and 20 darks per session
Processing: Pixinsight – SPCC, DBE, SPCC, BlurXT, NoiseXT → Linear_UVIR
MStr, GHS, HST, PMath MStr + GHS + HST → Stars_UVIR
Linear_UVIR, StarXT → Starless_UVIR
SPCC, DBE, SPCC, BlurXT, NoiseXT → Linear_LUlt
Linear_LUlt StarXT → Starless_LUlt
PMath ~(~Starless_UVIR*~Starless_LUlt) → Starless
PMath ~(~Stars_UVIR*~Starless) → Blend, scale
Location: Darling Hill Observatory in Vesper, NY
