finally finished my latest big project (and imo my best work to date): 'Ghost of Cassiopeia' which I dubbed 'The Desire For Navi' because it looks to me like a spectral, ghostly set of hands reaching for Navi, shrouded in cosmic mist.

The 20 hours of integration time, followed by a lot of trial and error (leading to almost the same amount of processing time, lol), eventually produced this image. And to be honest... I think it is a banger. The object itself is so magnificent, with its high contrast, chaotic but majestic mist, and its overall ordered composition. And for me, it's somewhat the first time that I found a pleasing color balance.

I collected 11h H-Alpha (300s subs), 4h Oxygen-III (300s subs) 4h Blue (180s subs) and 1.5h RGB (60s subs each). As usual, H-alpha shows the most signal of those emission nebula, but IC63 seems to have a OIII signal as well. IC 59 on the other hand is a reflection nebula and justifies a longer Blue exposure (I took shorter subs, because of Navi's proximity and it's blue color). The actual image composition is more like an HOO, but I integrated the 60s Blue, the 180s Blue and the 300s OIII together as "artificial OIII channel" and used it to create the bluish areas. The overall processing can be summarized as:
• stacking (APP) • Ha BXT, SXT, NXT (PI) • OIII together with Blue BXT, SXT, NXT (PI) • combine Ha and OIII as HOO (APP) • color adjustments, camera raw filter, local contrast enhancement, selective sharpening (PS) • combine RGB (APP) • reduce stars to 75% (APP) •  BXT, NXT (PI) •  extract RGB stars (SXT in PS), apply saturation and overlay with narrowband image (PS) •  further reduce star size (PS - Astronomy Tools) • HLVG (PS)

The main contrast comes sorely from the Ha-stack, which already shows incredible details:


Done with my trusty old SkyWatcher PDS200. My EQ6-R carries it soo smoothly after I tuned it, which resulted in an average guiding RMS of 0.47" for this object and HFR values of below 2.1 @750mm and 300s subs. So I will definitely stick with this "entry level" telescope... never change a running system, right?

Description Source: The Ghost (IC 63 & IC 59) are an emission and reflection nebula in the Northern constellation of Cassiopeia at a distance of 550 light years from Earth. The nebula is crafted by the intense stellar winds of the central blue supergiant star γ Cas (Navi). This star is 19 times more massive and 65 000 times brighter than our Sun. It also rotates at the incredible speed of 1.6 million kilometres per hour — more than 200 times faster than our parent star. This frenzied rotation gives it a squashed appearance. The fast rotation causes eruptions of mass from the star into a surrounding disk. This mass loss is related to the observed brightness variations. The radiation of Gamma Cassiopeiae is so powerful that it even affects IC 63, sometimes nicknamed the Ghost Nebula, that lies several light years away from the star. The hydrogen within IC 63 is being bombarded with ultraviolet radiation from Gamma Cassiopeiae, causing its electrons to gain energy which they later release as hydrogen-alpha radiation — visible in red in this image. This hydrogen-alpha radiation makes IC 63 an emission nebula, but we also see blue light in this image. On the other hand IC 59 exhibits a blueish color due to the fact that it reflects starlight from the massive star. Both nebulae are being eroded by the intense winds of Gamma Cas and eventually they will disappear.