What makes the star really stand out, however, is its eighth- magnitude (just barely, 7.51) companion, an orange class K (K7) dwarf. Star colors are subtle. But put two stars of even somewhat different color together, especially if there is a brightness difference, and the contrast can become quite intense. Eta Cas A (the brighter) and B thus put on a fine show through even a small telescope, the pair an easily-resolvable 11 seconds of arc apart.
Achird (stars.astro.illinois.edu)ACHIRD (Eta Cassiopeiae). At almost fourth magnitude (3.44) and faint to the eye, and not a part of the traditional outline of Cassiopeia, Achird is often neglected.