What it is
IC 63 is a small emission and reflection nebula about 550–600 light‑years away in Cassiopeia, positioned very close (in the sky) to the bright star Gamma Cassiopeiae (Navi). It is part of a broader nebulous complex (often including nearby IC 59) that sits in the middle of Cassiopeia’s familiar W‑shaped asterism.
Why it looks “ghostly”
The nebula’s red glow comes from hydrogen gas ionized by intense ultraviolet radiation from Gamma Cassiopeiae, which then re‑emits light in the H‑alpha line. The fainter blue‑gray regions are starlight from Gamma Cassiopeiae reflected off surrounding dust, giving it a wispy, ghost‑like appearance in deep astrophotography.
Observing and imaging
On the sky, IC 63 lies just off Gamma Cassiopeiae, making it easy to point to but challenging to see visually because the nebula is very dim and the star is very bright. Visual detection generally needs dark skies and a moderate to large aperture; for imaging, long total integration time and careful handling of Navi’s glare are key, often using narrowband H‑alpha plus broadband RGB/LRGB data.
Basic facts
- • Common names: Ghost of Cassiopeia, Ghost Nebula (IC 63)
- • Type: Emission plus reflection nebula (molecular hydrogen and dust)
- • Distance: Roughly 550–610 light‑years
- • Apparent size: About 10 arcminutes across for IC 63 itself
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