Constellation of the Month: Leo (the Lion)

 

Leo is one the more easily discernible constellations, high in the southern sky in temperate northern latitudes during the spring evening.  It has a first magnitude star, Regulus (a double star 77 light-years distant), at Leo's southwestern corner...Denebola (36 light-years away), at magnitude two, is on the east end, representing the lion's tail.  You can get a vague idea of what Leo is supposed to picture: a crouching or sitting lion facing the right (west).  Leo is a zodiac constellation, meaning that it is a section of background to the projection of the solar system's orbital planes through which we see the planets, our moon, and the sun...faint Cancer lies to its west and expansive Virgo to the east.  On its southern side are five Messier deep space objects: M65, M66, M95, M96, and M105.  They are all spiral galaxies.  In my memory Leo stands as one of the very first constellations I learned and recognized in the night sky long ago, when I was seven and my father introduced them to me one evening in April of 1964...