Leo is the bringer of Spring, arriving in mid-February and, although not as prominent as Winter's Orion, is nevertheless a dominant constellation with a recognisable asterism. The most prominent star, Regulus, forms a triangle with Procyon and Alphard (alpha Hydrae). For binocular study Leo has a number of interesting objects: binaries, variables, and deep sky objects. Start with Regulus, which is a binocular double.
Alpha Leonis is now called Regulus, as named by Copernicus. Previously it was known as Sharru, "King", and before that it went by the auspicious name of 'Guardian of the Heavens'. The Romans called it Cor Leonis, the Lion's Heart. Regulus is easily found, as it is one of the brighter stars of the early spring. The blue-white star is seemingly isolated, but it has a deep yellow companion -- a dwarf -- quite faint at 7.9 visual magnitude, and quite wide with a separation of 177". Large telescopes will show that this dwarf has its own companion, a very faint 13th-mag dwarf. Since Regulus is found so close to the ecliptic, it is one of the few bright stars occasionally occulted by the moon.
Beta Leonis is named Denebola, "The Lion's Tail". This second-brightest star in Leo at 2.14 visual magnitude, is 36 light years away. Denebola is 25º east of Regulus, and slightly north. It's easily found with the naked eye. Between Regulus and Denebola is the fainter theta Leonis. Placing theta at the top of your glasses, you'll see iota near the bottom, and in between are M65 and M66.
Gamma Leonis, "Algeiba" (perhaps erroneously, as the name means 'The Forehead'). Flamsteed and others in the seventeenth and eighteenth century called the star Juba, 'mane', a much more sensible designation. Gamma is eight degrees north of alpha Leonis, and slightly to the east. In the same FOV is zeta. The stars to the west of zeta (mu, epsilon, lambda, and kappa) are collectively called The Sickle. These stars form the top of the mane and Leo's face. Gamma Leonis is a fine double (gamma1 and gamma2) with an orbit of 618 years. At J2000.0 the companion was at a position angle of 125º and separation 4.4" To the east of gamma is delta Leonis, Zosma, which once had a better name, Duhr, meaning the Lion's Back.
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