Above: Comet Wirtanen 46P photographed from Shap, Cumbria, late on Dec 3rd, using a Canon 700D DSLR with a 135mm lens, on a sky-tracking. The image is a processed stack of 30 individual images. Photo: Stuart Atkinson
After teasing us for the past couple of weeks, hiding behind the muck and murk that lingers above the horizon, Comet Wirtanen (“46P”) is now – finally! – reaching a good altitude in the sky after dark and is well-placed for observation from the northern hemisphere, and with clear skies forecast for much of the UK tonight here’s how you can see it for yourself.
Luckily, the comet is not too hard to find because it is quite close to one of the most famous and easily-spotted constellations in the whole of the sky: Orion, The Hunter. With his distinctive “belt” of three blue-white stars, Orion is now rising in the east as soon as darkness falls, and by mid- to late-evening it is dominating the eastern sky – and Comet Wirtanen can be found just to the upper right of it.
So how do you find it? Is it obvious in the sky? Well, many media reporters are illustrating their coverage of this story with stunning images showing a bright comet, with a long tail, blazing in the sky, and something like that would be VERY obvious – but sadly, Wirtanen looks nothing like that! If you look at it through a small telescope or a pair of binoculars you will just see a round smudge, like a large out-of-focus star, rather than a bright star with a beautiful tail streaming away behind it. The picture below shows what to expect, and what you will definitely not see…!
But it’s not all bad news. As comets go, Comet Wirtanen is actually quite bright. Most comets never get bright enough to see without a telescope, or at least a pair of binoculars, but the latest reports say that comet Wirtanen is now brighter than 4th magnitude, which suggests it should be easily visible to the naked eye, and indeed many experienced comet observers are now reporting that Comet Wirtanen is bright enough to be seen with their naked eye. But of course it’s not that simple. Many of those observers are blessed with very dark skies and are not looking for it from the middle of light-polluted towns and cities like most people – and they know what they’re looking for, too! If you’re looking for Comet Wirtanen from your back garden, or the park up the street, or maybe from a dark lay-by up the road it probably will not be visible to your eye alone, and you’ll need a pair of binoculars to spot it. (Having said that, if you do live somewhere blessed with a dark sky by all means have a go – you might see it as a small, misty smudge to the upper right of Orion.)
Whether you’re planning on looking for it with just your eyes, your binoculars or small telescope, Orion will be a great guide for you if you want to see Comet Wirtanen tonight – its stars can be used as pointers to guide you towards it, as the chart below shows.
You can also use the V-shaped Hyades star cluster as a pointer. However you come to it, having found the right area of the sky, slowly, SLOWLY sweep your binoculars or telescope over the area. If you see something that looks like a round(ish) misty patch, like a small, faint cloud, that’s it, that’s the comet. 🙂
Over the coming week the comet will climb higher in the sky, and next weekend it will actually pass between the Hyades and Pleiades clusters, but the weather forecast for then is not good so try to see the comet tonight, it might be your last chance for a while.
Good luck – and let us know if you track down Comet Wirtanen!