Messier 20 in Sagittarius, the Trifid Nebula

NGC 6514, M20, the Trifid Nebula and NGC 6531, M21, in Sagittarius.

The Trifid nebula is an unusual combination of objects

containing an open cluster, an emission nebula (red), a

reflection nebula (blue), and dark nebulae (the veins).

Date:  23 June 2025

FOV:  cropped to 100' × 66' 40"; the angular size of M20 is about 28'

Telescope:  Stellarvue SVX102T + SFFX-1 (737mm, nominally 714mm f/7)

Guiding:  ZWO ASI120MM mini mono guide camera,

Stellarvue F050G 50mm guide scope

Computer:  ASIair pro Raspberry Pi

Mount:  iOptron CEM40

Camera:  ZWO ASI6200MC Pro Cooled (-10°C) Color CMOS with gain 100

Pixel size:  3.76 μm

Resolution:  1.052 arcsec/pixel

Filter:  Optolong UV/IR cut

Stacking:  fifty 240 second frames using PixInsight

Total Time:  3 hours 20 minutes

Processing:  Pixinsight – SPCC, DBE, SPCC, BlurXT, NoiseXT → Linear

HTS, GHS, MStr, PixelMath MStr + GHS + HST → Stars,

Linear, StarXT, HTS, GHS, MStr,

PixelMath MStr + GHS + HST → Starless, HDRMST6PhLm

PixelMath ~(~Starless*~Stars) → Blend, Sat, DynCrop/Scale

Location:  Cherry Springs State Park near Coudersport, PA