Square of Pegasus easy to spot in northern sky

This week I would like to encourage you to head out after sunset and explore some of the constellations on show in the northern sky. The moon was new yesterday morning which means its light will not interfere with your view.

The very distinctive square of Pegasus is easy to spot, low in the north as the sky darkens. Pegasus is the seventh-largest constellation in the heavens. Pegasus represents a winged horse tamed and ridden by Bellerophon. According to Greek mythology he slew the fire-breathing triple-headed Chimaera that had been terrorising parts of Lycia. The name of each star in the square is derived from Arabic. Markab translates to "shoulder", Scheat means "shin", Algenib is "side", while Alpheratz is "navel".

One thing I always like to do when stargazing is to compare the colours of stars. Three of the stars in the square are blue-white in hue but the star Scheat has a distinctly orange hue. This is because its surface temperature is a lot cooler than the other three stars.

A good test of your eyesight is to see how many dim stars you can count inside the square of Pegasus. Some people claim to have seen as many as 17 dim stars in this part of the sky with their unaided eyes.

Once you have scouted the square for faint stars, cast your gaze to the left of Pegasus. Between the stars Enif and Altair are two smaller constellations. Tiny Delphinus is the easier of the two to spot. Its distinct diamond-shaped group of stars represents the dolphin who, according to legend was the messenger of the sea god Poseidon.

Equuleus is a word that has occasionally helped me get rid of a surfeit of u’s in Scrabble. However, this small constellation (only the southern cross is smaller) is otherwise entirely unremarkable. The origin of its name is lost in the mists of time, but its name translates as “little horse”. To locate this cosmic foal, look for a dim triangle of stars roughly halfway between Delphinus and the star Enif in Pegasus.

 - Ian Griffin

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