The chart above looks directly overhead at nightfall or early evening in May, as seen from a mid-latitude in the N. Hemisphere. It’s as if we’re viewing the sky from the comfort of a reclining lawn chair, with our feet pointing southward. The constellation Leo the Lion stands high in the southern sky, while the upside-down Big Dipper is high in the north. Notice the Big Dipper and Leo. You can use them to star-hop to to the constellation Canes Venatici, the Hunting Dogs.
Many people know how to find Polaris, the North Star, by drawing a line through the Big Dipper pointer stars, Dubhe and Merak. You can also find Leo by drawing a line through these same pointer stars, but in the opposite direction.
Extend a line from the star Alkaid in the Big Dipper to the star Denebola in Leo. One-third the way along this line, you’ll see Cor Caroli, Canes Venatici’s brightest star. A telescope reveals that Cor Caroli is a binary star – two stars orbiting a common center of mass.
Cor Caroli (Latin for “Heart of Charles”) is named in honor of England’s King Charles I, who had his head cut off in 1649. The name first appeared on English star maps in the late 1600’s as Cor Caroli Regis Martyris (“Heart of Charles the Martyr King”). King Charles II, the son of King Charles I, founded the Royal Greenwich Observatory.
Bottom line: Star-hop to Canes Venatici, the Hunting Dogs, tonight! You can do it, if you can find the constellation Leo and the famous Big Dipper asterism.