Cigar Galaxy (Messier 82)

Source: Wikipedia Commons © Pablo Carlos Budassi

The constellation of Ursa Major is famous for its seven brightest stars, which make up the famous naked-eye asterism the Big Dipper – also known as the Plough – including the close pair of Mizar and Alcor and the twin ‘Pointers’ that direct the observer in the direction of Polaris, the Pole Star, in nearby Ursa Minor. But behind the stars of this northern constellation, which hangs almost overhead after sunset on these brisk, spring nights, there are some beautiful deep-sky objects for telescope users to enjoy.

Some distance away from the Big Dipper, the close pair of galaxies Messier 81 and Messier 82 are a favourite of many owners of small telescopes, but larger instruments show lovely detailing in the arms and centres of these faraway galaxies. Just beneath the bowl of the Big Dipper, the Owl Nebula (Messier 97) is a very popular target for serious astrophotographers because it really does look like an owl’s face in long-exposure photos. Yet like all planetary nebulae – the glowing shells of deceased stars – its appearance in an eyepiece is much more subtle, and you’ll only see its resemblance to the face of the wise old bird of prey through a highpower eyepiece in a large telescope.

Owl Nebula (Messier 97)

Source: Wikipedia Commons © Göran Nilsson & The Liverpool Telescope

Deep sky challenge

“The close pair of galaxies Messier 81 and Messier 82 are a favourite”

1 Bode’s Galaxy (Messier 81)

Although this +6.8 spiral galaxy is bright enough to be visible in binoculars as a tiny smudge, larger instruments are needed to show its spiral arms and bright core. It is around 12 million light years away.

2 Cigar Galaxy (Messier 82)

Also known as the Cigar Galaxy, it’s much smaller and fainter than its more obvious neighbour, which lies just over half a degree away. On a night of good seeing a large-aperture telescope reveals light and dark patches.

3  Messier 108

Shining at tenth magnitude, this beautiful barred spiral galaxy is visible as an elongated smudge in six-inch telescopes. Instruments of a larger aperture will reveal interesting mottling along its length. It is over 45 million light years away.

4 Owl Nebula (Messier 97)

You’ll need at least a mediumaperture telescope to see the two dark ‘eyes’ of this planetary nebula because of its magnitude and low surface brightness. Through a large telescope you’ll see fascinating dappling.

5 Messier’s Mistake (Messier 40)

This object is not a galaxy, nebula or cluster, but a close pair of ninth-magnitude stars. It is an optical line-of-sight double rather than a genuine binary star. It is one of the best known anomalies in Messier’s famous catalogue.

6  Messier 109

Some 82 million light years away and shining dimly, this barred spiral galaxy is a small, pear-shaped blur through small telescopes. Away from light pollution, telescopes six inches or larger bring out the subtle glow of its curling spiral arms.

Bode’s Galaxy (Messier 81)

© NASA, ESA and the Hubble Heritage Team