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Moon and Regulus

January 18, 2014

Many of the constellations are tough to decipher. Few modern-day skywatchers see a charioteer in the stars of Auriga, for example, or even a ram in Aries. In a few cases, though, the picture shines through.

A good example is Leo, which stretches out beside the Moon when they climb into good view by mid-evening. Leo’s brightest star, Regulus, is close to the upper left of the Moon.

It takes little imagination to fit together the stars of Leo to form a crouching lion, with its head at the top and its tail below.

Regulus is the lion’s heart. His head and mane form a big arc to the upper left of Regulus that’s known as the Sickle. It’s an asterism — an identifiable shape that doesn’t represent a whole constellation. The most famous asterism is the Big Dipper, which is part of Ursa Major, the great bear.

After Regulus, the sickle’s next-brightest star is Algieba, which connects the mane to the lion’s body. It consists of two aging giant stars in an extended orbit around each other. Both stars are much bigger, brighter, and heavier than the Sun. And although they’re just one-tenth of the Sun’s age, they’re nearing the ends of their lives.

The star at the tip of the sickle’s blade is Algenubi, from an Arabic name that means “southern star in the lion’s head.” It, too, is a stellar giant.

These and other stars perform double duty, outlining two easy-to-see pictures: the wide curve of a sickle and the prominent mane of a lion.


Script by Damond Benningfield, Copyright 2013

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