Deep sky challenge
Push your telescope to the limit with our choice of targets
The constellation of Perseus, which looks a little like an inverted letter 'Y', rides high in the night sky for northern hemisphere observers at this time of year, and it is packed with amazing objects to see with your telescope.
Perseus sits on the faint river of the Milky Way, and it is famous for two objects in particular: a short-period variable star and a fine 'double' star cluster. Whereas the 'Demon Star' Algol, one of the most famous of all the short-period variable stars, is a naked eye object, the double cluster Caldwell 14 needs at least binoculars to see well, and a small telescope will show it beautifully.
Apart from these two wonderful objects, there are also several other open star clusters and a faint and challenging nebula to be seen in this part of the sky. There is therefore, something for everyone to see in the region of Perseus.
The Double Cluster (Caldwell 14)
Open star clusters NGC 869 and NGC 884 – known collectively as Caldwell 14 – lie close to each other and can been seen easily in the same field of view of a low-power eyepiece.
Algol (Beta Persei)
Known as the 'Demon Star', Algol is in fact a triple-star system. The stars regularly block each other’s light, which causes a ‘flicker’ between magnitude 2.1 and 3.4.
The Spiral Cluster (Messier 34)
A bright, large open cluster that lies five degrees northwest of ‘Demon Star’ Algol. Messier 34 is easily resolved even through 10x50 binoculars, thanks to its magnitude of 5.5.
NGC 1342
Between 100 and 150 stars make up the group, which – under good night sky conditions – are apparent even to the unaided eye, as the cluster provides a combined magnitude of 6.7.
IC 348
Due to the diffuse nature of this 2-millionyear-old star-forming region, it’s likely that you’ll need a filter to pick out its wispy appearance that surrounds its binary star system.
California Nebula (NGC 1499)
The California Nebula is a challenging star formation to observe visually – you’ll need a H-Beta filter to draw out the nebula’s structure as well as a telescope with a decent-sized aperture.