γ Cephei


Gamma Cephei is named Er Rai, the Shepherd, although now it serves to mark the tip of the dunce cap which the humbled king is forced to wear.

The star is an orange subgiant 45 light years away. In another 2000 years this star will become the pole star.

Gamma Cep is found by moving from kappa Cep two binocular fields due east, or from beta Cep two binocular fields northeast. In other words, beta, kappa, and gamma form a large naked-eye upside-down triangle.

The star on the southern edge of your view, pi Cephei, is a difficult double: 4.6, 6.8; 355º, 1.1"


There is one more object in Cepheus to investigate—not a binary but a notable star cluster.

Moving north one and a half binocular fields gives you NGC 188. The cluster is five degrees from the North Pole, with the bright 2 UMi its closest neighbour.

This is a fairly dispersed globular cluster, notable in that it is the northern-most cluster as seen from Earth, and it is the oldest visible open cluster. Once claimed to be as old as 15 billion years, the consensus now is five to seven billion years.

There are over a thousand faint stars, mostly 12-15 magnitude, which produces an apparent magnitude of about 8.1. Only larger telescopes will bring out individual stars, many of which are yellow giants.

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