ABSTRACT
The leading star of Perseus is Alpha, an F-type giant 6,000 times as luminous as the Sun and 620 light-years away. In the photograph it is clearly “off-white”, though a yellow cast is not pronounced. However, the most famous star in Perseus is Beta, the prototype eclipsing binary; apart from Mira Ceti, it was the first star known to vary in light. The double cluster NGC 869-884 is the “show-piece” of Perseus; it is known as the Sword-Handle, or as Chi-h Persei. Rho is a semi-regular star, with a rough period of around 40 days and an extreme magnitude range of from 3 to 4; useful comparisons, both in Perseus, are Kappa and Xi. The secondary star is of type G, and 3 times as luminous as the Sun; its diameter is over 5 million kilometres, though it is less massive than the primary.
