The Ghost of Cassiopeia

September 29, 2022

Gamma Cassiopeiae (γ Cassiopeiae) or just "Gamma Cas" and sometimes "Navi" is the center star in the "W" asterism that makes up the constellation Cassiopeia, one of the easiest constellations to find in northern hemisphere skies. It's an eruptive variable star—which sounds exciting for a star; this basically means it is unpredictably variable, with an apparent magnitude between 1.6 and 3, and does not follow an observed repeatable cycle. The two nebulae IC63 ("Ghost Nebula", below γ Cass in this rotation) and IC59 (above) are fairly dim, but do reflect light from γ Cass and other nearby stars, and IC63 exhibits some emission properties, gaining energy and then emitting it as light. Gamma Cas and both nebulae are about 550 lightyears away, very close to us. In terms of distance from Earth, this is one of the closest Deep Sky Objects I have ever captured, and M45, the Pleiades, at around 450 lightyears may actually be the closest. Imaging Notes: 93 x 180-second subs across Red, Green, Blue filters (Astronomik Deep Sky RGB), ZWO ASI1600MM-Pro monochrome camera running at -10C, ZWO AM5 EQ mount, William Optics SpaceCat 51 apochromatic refractor, ZWO ASI290MM guide camera with OAG.