The instantly recognisable five-star M-shaped pattern of stars representing the constellation Cassiopeia (pronounced kas-ee-uh-pee-uh) lies almost overhead in the early evening as seen from the British Isles over the festive period. Cassiopeia is rich in wonderful double and multiple stars, so here’s our guide to some of the best for typical backyard telescopes.
This glorious spiral galaxy is known as NGC 24, measures some 40,000 light-years across and lies about 25 million light-years away in the southern constellation of Sculptor. However, there may be more to this picture than first meets the eye: 80 percent of NGC 24’s mass is thought to be held within an invisible dark matter halo.
This infrared image from ESA’s Herschel Space Observatory shows the region known as Vulpecula OB1, a ‘stellar association’ in which a batch of truly giant ‘OB’ stars is being born 8,000 light-years away in the constellation of Vulpecula (The Little Fox). There is enough material here to build stars for millions of years to come.
Discovered in 1784 by William Herschel, NGC 4394 is the archetypal barred spiral galaxy, with bright spiral arms emerging from the ends of a bar that cuts through the galaxy’s central bulge. Some 55 million light-years from Earth, the galaxy lies in the constellation of Coma Berenices. NGC 4394 is considered to be a member of the Virgo Cluster.
Elliptical galaxy NGC 3610 is the most prominent object in this amazing Hubble image — and a very interesting one at that! Discovered in 1793 by William Herschel, it was later found that this galaxy contains a disc. This is very unusual, as discs are one of the main distinguishing features of a spiral galaxy. And the disc in NGC 3610 is remarkably bright.
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