monthly skyguide, free star charts, constellation star charts, sky guide

Perseus - the Hero

Mythology - Perseus was the son of Zeus and Danaë, conceived as she was locked up by her father Acrisius. Mother and son escaped ina floating chest to the kingdom of Polydectes. The king fell in love with Danaë but she refused to marry him. Perseus intervened and was dispatched on a mission to bring back the head of Medusa as a wedding gift. Helped by the gods who gave him a reflective shield, a helmet of invisibility, a special bag and winged sandals, he succeeded in beheading the gorgon and flew back to his mother's side. On the way he rescued Andromeda from the sea-monster Cetus and gained her hand in marriage. He returned to the wedding feast and opened up the bag containing the head of Medusa while commanding his mother to look away. Everyone else was turned to stone. Much later he took part in a tournament and threw a discus which killed Danaë's father, fulfilling the very prophesy that he had locked her up for in the first place!
Stars - The most interesting star to the casual observer is the winking “demon” star, beta perseii or Algol. It is traditionally said to represent the eye of Medusa, the gorgon beheaded by Perseus. The ancient Arabs were aware that its brightness varied, but it was John Goodricke, a British astronomer, who first measured its light curve in 1782. Normally this star is mag. 2.1 but every 2.87 days it fades down to 3.4. It is a fine example of an eclipsing binary system - two stars in orbit about a common centre of gravity, one bigger and brighter than the other. You should be able to see it dim during a week of observations by comparing it to nearby reference stars.
Deepsky - Perseus plays host to a beautiful double cluster comprising NGC 869 and 884. The naked eye can pick this out quite clearly in the region between the head of Perseus and the “W” of Cassiopeia. Binoculars reveal hundreds of stars clumped together in two adjacent swarms. M34 is a fine open cluster of 80 stars best seen through binoculars or a rich-field telescope.
Visibility - Perseus is visible from November through to March