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Constellation Cepheus looks like a house


Tonight for August 5, 2015

The constellation Cepheus represents a King. It is faint, but its distinctive shape makes it easy to locate if you look in the north on August and September evenings. Tonight, be sure to look for Cepheus during the evening hours, because the bright waning gibbous moon will rise at mid-to-late evening tonight (Friday, August 15). After that, the moon will continually rise later after dark until it turns new on August 25.

What is the ecliptic?

At nightfall Cepheus appears to the right or upper right of Polaris, the North Star. Then this constellation rotates around Polaris in a counter-clockwise direction during the night. It swings high over Polaris after midnight, and then sweeps to the left side of Polaris before dawn.

Cepheus resembles the stick house we all drew as children – and that children today still draw – with a square for the base and a triangle for the roof. In the case of Cepheus, the tip of the roof (a star known as Gamma Cephei, or Errai) points generally northward.

Star Errai: Future North Star

In the sky, “northward” always means “toward the sky’s north pole,” or toward Polaris. Thus the roof of the house in Cepheus is pointing mostly north, even though – as darkness falls – that means it’s pointing sideways and downward.

Sky chart of the constellation Cepheus the King

The constellation Cepheus the King. Click here for a larger chart

In Greek mythology, Cepheus represents a King of Ethiopia. To find Cepheus, you might want to locate a more prominent constellation, Cassiopeia the Queen. For more about Cassiopeia, see yesterday’s sky chart.