Popular Astronomy

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Cassiopeia, the mythological queen

Pity poor Queen Cassiopeia. She has to spend her time looking like a letter W – when she isn't looking like a letter M instead, that is. But we shouldn't mock. It would be very strange if the stars in the sky actually did form pictures like a join-the-dots puzzle. And let's face it, whenever did you see one of those that you couldn't guess anyway, without even bothering to find the numbers? So we shouldn't be too surprised that the names of the constellations bear no resemblance to their shapes.

But there is a story behind Cassiopeia, the queen who fancied herself something rotten. She spent hours preening herself in front of the mirror. Sound like anyone you know? In fact, she really got up the noses of the sea nymphs, who got the Old Man of the Sea to punish her country. As a result, and you may not believe this (but then we are talking about Greek myths), she tried to sacrifice her beautiful daughter Andromeda to the sea monster. Fortunately the hero Perseus (a nearby constellation) was on hand to rescue Andromeda.

As a punishment for all this, Cassiopeia was condemned to hang upside down in the sky, which is how she appears on the old star maps. But really, to be regarded by all and sundry as a letter W is just as bad, only one step better than having a face like a bag of monkeys.

So here is the map. Most of the time, the main stars of Cassiopeia look like a W, but when it is high in the sky you might see them as an M.


For hints on understanding the star map, please click here

Things to look for in Cassiopeia

Because Queen Cass is in the Milky Way, this is a good area for just gazing at with binoculars. There are some rather good star clusters which you can see with binoculars quite easily if you have dark skies. NGC 663 is just about the brightest and easiest to see with binoculars. Don't expect too much, but even with some light pollution you should be able to spot it, because its stars are comparatively bright and spread out.

A lot of the books talk about the cluster M52, but with binoculars this is a bit harder to see as its stars are much fainter, though if you have a small telescope it should be easy to see. NGC 7789 is also faint, but worth a look.

NGC457. Credit Robin Scagell
But the best of all, if you have a telescope, is NGC 457. This cluster is one which can actually make people laugh when they see it, or at the very least twitch their mouths. It surrounds a fifth magnitude star known as Phi Cas, the one just below Ruchbah on the map. With binoculars it is a disappointment, but in a small telescope you can see a line of fainter stars and two brighter ones. But the great thing is when you give the cluster its nickname of 'the ET Cluster'. Once you see the stick figure with long, gangling arms and two great luminous eyes, it will be a favourite (right).

Cassiopeia is also the constellation in which two very interesting variable stars lay. Gamma Cassiopeia and Rho Cassiopeia. If your interested in observing these variable stars then please do contact our variable star section director for more advice on observing them

Can't see any of them?

Don't worry – these objects do require fairly clear and dark skies. If you are having problems finding them with binoculars from your location, try again on a clearer night, or wait until Cassiopeia is virtually overhead. Keep as well away from lighting as possible, and make sure your surroundings are as dark as you can get them.

A small telescope with a magnification of about 25 – 50 will be better than binoculars. If all else fails, you will need to find a darker location.