Starwatch: Leo the lion dominates the northern hemisphere

The northern hemisphere’s spring evenings are dominated by the unmistakable outline of Leo, one of the few constellations that resembles the creature it represents, the lion. Leo is most easily identified by its distinctive “backwards” question mark, referred to by astronomers as the “sickle” asterism and representing the head of the lion. The chart shows the view looking high in the southern sky from London on 27 April at 22.00BST, although the view will be essentially the same all week. Recognised since antiquity, the constellation has long been associated with the figure of a lion. Enshrined in western written culture as one of the original 48 constellations listed by Ptolemy in the second century, it has a rich mythological tradition. In Mesopotamia, it was associated with the lion ridden by the goddess Ishtar, while the ancient Egyptians linked it to the annual flooding of the Nile River, which occurred when the sun passed through this region of the sky. In Greek mythology, Leo represents the fearsome beast slain by Heracles (Hercules) as the first of his 12 labours. The constellation’s brightest star is Regulus, a brilliant blue-white star that sits almost exactly on the ecliptic, which is the path traced by the sun, moon and planets across the sky. From the southern hemisphere, Leo is clearly visible in the northern sky.