Cepheus

When and where to look for Cepheus

Cepheus crosses the meridian — its highest point in the sky — at local midnight around August, which makes the months from July to September the easiest time to find it in the evening. It spans declinations +57.0° to +77.6°, so visible from everywhere north of about 12°S.

The quickest way to find it is to open the live AR sky map and point your phone at the sky — if Cepheus is above your horizon right now, its figure is drawn in the position it genuinely occupies above you.

Brightest stars in Cepheus

Magnitude runs backwards: lower numbers are brighter, and anything below about 6.5 is beyond the naked eye under a dark sky.

What Cepheus is made of

The catalogue lists 158 stars within Cepheus, of which 158 are magnitude 6.5 or brighter — the limit of what an unaided eye picks up under a genuinely dark sky. The rest need binoculars or a telescope.

Spectral make-up

Spectral class is a temperature ordering, running from O at around 30,000 K down to M below 3,500 K. A constellation is a direction, not a group, so this is simply what happens to lie along that line of sight.

The closest catalogued star in this direction is HD 223778 at 35.5 light years. The most distant is 14 Cep at roughly 3,048 light years — stars that appear side by side here are nothing of the sort.