4100 LY

Here I have added SII to my previous bicolor data to produce a Hubble palette version of M8. This target is fairly bright with all 3 narrowband filters. The chief advantage of this version over the bicolor one I recently posted is that adding in the SII allowed me to process to see much more detail in the nebular core. There’s a surprising amount of detail in the SII data. M8 never gets more than 25° above my southern horizon and I’ve battled monsoonal moisture all summer.

Date: 2 July, 20 & 23 Aug 2019
Subject: M8, Lagoon Nebula
Scope: AT8IN+High Point Scientific Coma Corrector
Filters: ZWO 31 mm diameter unmounted 7 nm Hα, OIII
Mount: EQ-6 (EQMOD 2.000j)+PEC
Guiding: Orion Thin Off-axis Guider + ASI120MM-mini +PHD 2.6.6 (Win 10 ASCOM)
Camera: ASI1600MM-Cool, -20 °C, Gain 139 Offset 21
Acquisition: Sequence Generator Pro 3.0.3.198
Exposure: 20x300 Hα, 11x300 OIII
Stacking: Deep Sky Stacker 4.2.2 (64-bit) dark+flat+bias, κ-σ stacking with κ = 1.5.
Processing: StarTools 1.4.352: Cropped, wiped, developed, HDR optimized, deconvoluted, and untrack denoised the Hα, OIII, and SII data separately. Combined using Annie’s Astro Actions Hubble Palette action. Curves & Levels several times, followed by Local Contrast Enhance. Created a synthetic luminance layer by combining the Hα and SII (the focus was not great for the OIII). Finished with some layer-masked Curves to bring up the outer regions without messing up the core.