Constellations · Constellation · Persei · Per
Constellation
Perseus
The hero with Medusa’s head in his hand. Her evil eye is Algol, the “Demon Star”, which winks every three days.
- Genitive
- Persei
- Area
- 615 square degrees · 24th of 88
- Brightest star
- Mirfak · magnitude 1.79
- Naked-eye stars
- 163 brighter than magnitude 6.5
- Highest at midnight
- late November
Myth
Flying home on winged sandals from killing Medusa, Perseus saw Andromeda chained to the rock and turned the monster to stone.
Look for
Algol fades to a third of its brightness for a few hours every 2.87 days, as a fainter star eclipses it. Compare it with its neighbours on two nights and you can catch it.
Look for
Between Perseus and Cassiopeia, the Double Cluster is a naked-eye smudge and a binocular glory. In mid-August the Perseid meteors radiate from here.