1. LEO
By Nina Saddler

2. The formation
Leo is the 12th largest constellation in size, occupying an area of 947 square degrees.
It is located in the second quadrant of the northern hemisphere (NQ2) and can be seen at latitudes between +90° and -65°.

3. The region
The neighboring constellations are Cancer, Coma Berenices, Crater, Hydra, Leo Minor, Lynx, Sextans, Ursa Major and Virgo.
Leo contains five Messier objects: Messier 65 (M65, NGC 3623), Messier 66 (M66, NGC 3627), Messier 95 (M95, NGC 3351), Messier 96 (M96, NGC 3368), and Messier 105 (M105, NGC 3379). It has 11 stars with known planets.

4. Cool information
There are two meteor showers associated with the constellation. The Leonids usually peak on November every year and have a radiant near the bright star Gamma Leonis. The January Leonids are a minor shower that peaks between January 1 and 7.
Leo belongs to the Zodiac family of constellations, along with Aries, Taurus, Gemini, Cancer, Virgo, Libra, Scorpius, Sagittarius, Capricornus, Aquarius and Pisces.

5. Myth
The Greeks associated Leo constellation with the Nemean Lion, the beast killed by Heracles during the first of his twelve labours. Both Eratosthenes and Hyginus wrote that the lion was placed among the constellations because it was the king of beasts.
The lion lived in a cave in Nemea, a town located to the south-west of Corinth. It was killing the local inhabitants and could not be killed because its skin could not be pierced by any weapons.
Hercules and the Nemean lion, photo: Andreas PraefckeHeracles could not kill the lion with arrows, so he trapped the lion in its cave, grappled with the beast and eventually choked it to death. He used the lion’s claws to cut off its pelt, and then wore the pelt as a cloak, complete with the lion’s head. The cloak both protected Heracles and made him appear even more fearsome.
In the sky, the six bright stars that form the shape of a sickle represent the lion’s head, and the brightest star in the constellation, Regulus (Alpha Leonis), marks the beast’s heart. Another bright star, Denebola (Beta Leonis) marks the tip of the lion’s tail. Algieba (Gamma Leonis), lies on the lion’s neck, even though its name means “the forehead.” Zosma (Delta Leonis) marks the lion’s rump.

6. Stars-regulus
Regulus – α Leonis (Alpha Leonis)-Regulus, Alpha Leonis, is the brightest star in Leo and the 22nd brightest star in the sky. It has an apparent visual magnitude of 1.35 and is approximately 77 light years distant.Regulus is a four-star system composed of two pairs of stars. Regulus A is a spectroscopic binary star composed of a blue-white main sequence star belonging to the spectral class B7 V, and a companion star which cannot be resolved, but is believed to be a white dwarf. The two stars complete an orbit around their common centre of mass every 40 days or so.

7. Stars-Denebola
Denebola – β Leonis (Beta Leonis)-Denebola is the second brightest star in Leo and the 61st brightest star in the sky. It is a main sequence star with the stellar classification A3 V. It has an apparent visual magnitude of and is approximately 35.9 light years distant from Earth. The star can easily be seen without binoculars.Denebola has 75% more mass than the Sun, 173% of the solar radius, and is 12 times more luminous. It is classified as a Delta Scuti variable, which means that its brightness varies slightly over a period of a few hours. Denebola exhibits variations in luminosity of magnitudes about ten times a day.

8. Stars-Algieba
Algieba – γ Leonis (Gamma Leonis) -Gamma Leonis is a double star in Leo. Its traditional name, Algieba or Al Gieba, comes from the Arabic Al-Jabhah, which means “the forehead.” The star is sometimes also known by its Latin name, Juba.Algieba is composed of a giant star with the spectral classification K1-IIIbCN0.5 and a dimmer companion star which belongs to the spectral class G7IIICN-I. The brighter giant is 180 times more luminous than the Sun and has an apparent visual magnitude of The G7 class star has a visual magnitude of 3.51, is 50 times brighter than the Sun, and has 10 times the solar diameter. The two stars have an orbital period of 500 years. A planet was discovered in the orbit of the primary star in November 2009.The Gamma Leonis system has a combined apparent visual magnitude of 1.98 and is approximately 130 light years distant from the Sun. It is easy to observe in a small telescope under good conditions and appears as a bright double star with orange red and greenish yellow components.

11. Cited