ABSTRACT
Cassiopeia is one of the most prominent of the northern constellations, and its W or M pattern, made up of Alpha or Shedir, Beta, Gamma, Delta and Epsilon makes it very easy to identify; over Britain and the northern United States and Canada it never sets. Cassiopeia is crossed by the Milky Way, which runs across the photograph from top left to lower right; the whole area is very rich, and there are several open clusters. Near Delta lie M103 and NGC 663; both are sparse, but easy to locate with binoculars. Forming a triangle with the K-type, rather orange Zeta Cephei are two fainter stars. One, Epsilon is a normal Main Sequence star, but the other, Delta, is astronomically one of the most important stars in the sky; it is the prototype Cepheid variable, with a range of from magnitude 3.5 to 4.4 and a period of 5.37 days.
