This week, head out of the city to a dark sky location and track down the constellation of Corona Borealis, the northern crown. It is a small, relatively faint constellation but one that has been recognised for millennia. Ptolemy listed it in his 2nd century catalogue of 48 constellations. In classical Greco-Roman mythology, the semi-circle of stars is said to represent the crown given to Cretan princess Ariadne by the god Dionysus. Other cultures see things very differently. The constellation has been variously described as a heavenly castle, a boomerang, a group of dancing sisters, a string of jewels and a broken dish.
To find the constellation, look west in the late evening and identify the bright orange star of Arcturus in Boötes, the herdsman. The star will be heading for the horizon, getting ready to set. From Arcturus, look diagonally upwards towards the body of Hercules, the hero. Corona Borealis will be sitting between these two larger constellations. Although faint, once identified it will be unmistakable. The chart shows the view looking west from London at 23:00 BST. Observers in the southern hemisphere will need to look north, and the constellation will appear upside down.
