Deep sky challenge
A ghostly nebula and a roseshaped star cluster await you
We’ve got some real observing challenges for our readers this month, with faint gems hidden among the bright, familiar stars of the much loved constellations of Perseus and Cassiopeia. However, with the sky staying bright until the very small hours at this time of year you’ll need to stay up late or get up early to see them.
NGC 7789 is a loose cluster popularly known as ‘Caroline’s Rose’. Discovered by Caroline Herschel in 1783, its many loops of stars and the dark gaps between them give it – some observers claim – a strong resemblance to a white rose. See what you think when you have it in the middle of your telescope’s eyepiece.
Messier 76 is a planetary nebula nicknamed the ‘Little Dumbbell Nebula’ and is infamous among deep-sky observers as one of the hardest to see of Messier’s catalogue of 110 objects. Definitely one for the owners of large-aperture ‘light buckets’ to try and hunt down.
Owners of small telescopes aren’t left out, however. The pretty little magnitude +5.6 cluster Messier 34 is worth looking at through any telescope at any time.
1 The California Nebula (NGC 1499)
NGC 1499 is quite large, but its very low surface brightness means it is hard to see in small telescopes. It is only seen properly through light-gulping medium- or large-aperture instruments.
2 NGC 559
This ninth-magnitude loose open cluster in Cassiopeia contains several dozen stars and is best seen in medium-aperture or larger telescopes. It is 3,700 light years away and approximately 4’ across.
3 Little Dumbbell Nebula (Messier 76)
Magnitude +10.1 M76 is one of the most difficult to find of all of Messier’s objects; only large instruments will show it clearly. Despite its nickname it looks more like a misty elongated patch than a twin-lobed dumbbell.
4 Messier 34
Just north of Algol, M34 is a very loose open cluster of 100 or so stars covering the same size area as the full Moon. Small telescopes give the best view of the trio of arms coming from its centre.
5 Messier 103
This magnitude +7.4 open cluster is one of the sky’s ‘hidden gems’. Small- and medium-aperture telescopes give lovely views of the ‘miniature Orion’s Belt’ across its centre, an orange star with an icy blue star on either side.
6 Caroline’s Rose (NGC 7789)
The stars in magnitude +6.7 NGC 7789 are so densely packed that some think it looks more like a globular cluster than a loose cluster. Either way, medium- and large-aperture telescopes are needed to see the stellar petals’ subtle outlines.
“Messier 34 is worth looking at through any telescope at any time”