NGC6888 — Crescent Nebula

Fri, 07 Nov 2025 21:00:00 +0100

NGC 6888, known as the Crescent Nebula, is a wind‑blown bubble in the constellation Cygnus. It forms where the fast, energetic outflow from the Wolf–Rayet star WR 136 rams into slower material ejected earlier in the star’s life, piling up gas into shock fronts and glowing filaments. It lies about 4.7–5 thousand light‑years away and spans roughly 20 × 10 arcminutes (about 25 light‑years across), with bright oxygen‑rich rims and a fainter hydrogen shell.

Discovered by William Herschel in 1792, the nebula sits in the rich Milky Way starfields of the Northern summer sky. For visual observers it is a demanding target that benefits greatly from O III or UHC filters; small telescopes under dark skies can reveal the brightest arc as a delicate crescent.

For imaging, broadband cameras respond well with a UHC filter that suppresses light pollution and enhances emission lines. Longer integrations uncover the subtle web of filaments and the contrasting colours: teal O III arcs wrapping around reddish H‑alpha structures sculpted by intense stellar winds.


Telescope	SkyWatcher 150/750P
Mount	motorised EQ3-2
Camera	Canon 600D (astro-mod)
Filters	Astronomik UHC 2"
Exposure	38 × 120 s + 78 × 120 s = 13,920 s (3 h 52 min)
Bortle	5
Moon	Waning gibbous (94.8%)
Processing	Siril, GraXpert, CosmicClarity, Gimp

NGC7380 — Wizard Nebula

Wed, 17 Sep 2025 21:00:00 +0100

NGC 7380 is a young open star cluster in the constellation Cepheus, embedded in the large emission nebula catalogued as Sh2‑142. In images they appear together as the Wizard Nebula. It lies roughly 7–8 thousand light‑years away and spans nearly 100 light‑years. The cluster was discovered in 1787 by William Herschel.

The nebula’s colours come from glowing ionised gases: red is mainly hydrogen (H‑alpha), while greens and blues trace oxygen (O III) and sulphur (S II), often combined in the so‑called Hubble palette. The wizard‑like outline is not a solid object; it is sculpted by intense radiation and stellar winds from young, massive stars, shaping clumps of gas and dust where new suns can still form.

For visual observers the target is fairly challenging; it reveals itself best in long exposures and narrowband imaging, which isolates the light of specific elements from the background. Northern‑hemisphere autumn nights favour the hunt for the Wizard, making it a rewarding, detail‑rich subject for practising data processing and colour mapping.


Telescope	SkyWatcher 150/750P
Mount	motorised EQ3-2
Camera	Canon 600D (astro-mod)
Filters	Astronomik UHC 2"
Exposure	27 × 120s (54")
Bortle	5
Moon	Waning Crescent (19.31%)
Processing	Siril, Prism Deep, CosmicClarity, Gimp

H II Region on AstroT3k

NGC6888 — Crescent Nebula

NGC7380 — Wizard Nebula