Earlier this month, we looked at Andromeda, who as part of the Greek myth, was chained to a rock for the sea monster Cetus to devour but was rescued by the hero Perseus.
This week we shift our attention to the constellation of Perseus, and specifically to a deep-sky object that can be seen under good conditions with the naked eye. The Double Cluster is a pair of adjacent star clusters that sit to the north of the main constellation.
The chart shows the view looking north-east at about 21.00 BST this week. You will need a dark sky, well away from street lamps, and some patience, so your eyes adjust to the dark.
Catalogued as NGC 869 and NGC 884, the clusters are both about 7,500 light years away. This means the light you see from them set out on its journey about 5500BC. They represent the combined light from many thousands of stars, and yet because of the vast distance their light has travelled, they appear only as faint smudges that are easily overlooked.
Unfortunately, the clusters are not visible from southern hemisphere locations such as Cape Town, South Africa or Sydney, Australia.
