Alfirk (Beta Cephei) -- Double Star in Cepheus
White & Blue Alfirk
Beta Cephei ranks as the finest double-star in the constellation of the King (Cepheus). The
accepted name of Beta Cephei is Alfirk which translates to “the stars of the flock [sheep]”.
This flock also consists of two other sheep, Alpha Cephei and Eta Cephei, but these stars no
longer carry the name of Alfirk – only Beta Cephei does.
Alfirk in the telescope has a bright white primary star and a distinctive blue secondary star.
With a separation of 14 arcseconds the pair are split in any sized telescope. The blue color
of the secondary (dimmer) star is intense and can be discerned even in my small 60mm f/15
refractor. In the 155mm refractor (used for the drawing) the blue is breath taking.
Alfirk is really a three-star system. The third star is so close to the primary that it remains
invisible in my 155mm refractor.