Comet SWAN seen from the UK

At last! Comet SWAN F8 has been photographed from the UK! That means it’s observable from mid-northern latitudes, so “northern observers” will now be heading in their droves before sunrise over the next week or so hoping to see it and take their own photographs.

The comet was photographed before sunrise by comet observer Nick James, who posted this image on the “Comet Watch” Facebook group.

Here’s some really useful technical info from Nick:

The picture was taken from a large playing field around half a mile from home. My NE horizon from home doesn’t go down that far. I took as much as I could carry on my bike and cycled out around 2:45 BS. This is a stack of 17 x 10s exposures which have been dark subtracted and flat fielded but no other processing as yet. Show in RAW mode on a Canon EOS550D at ISO400 using a Canon 200mm, f/2.8L lens stopped down to f/3.2. 10s was chosen since the sky starts to saturate at that exposure around 0230 UTC. The picture is a contrast stretched crop from the full frame.

So, here we go! The hunt is on! But a word of caution…

What is very clear from Nick’s photo is that Comet SWAN is NOT a naked eye object, despite what many reporters and Twitter accounts are saying on social media. It might technically be a naked eye object, with a magnitude of around 6, but its low altitude, proximity to the Sun and the bright sky it’s in all mean it is not visible to the naked eye and is at best a binocular object, only being “seen” so far by cameras taking long exposure photos.

But let’s be positive! The comet is now in the northern sky… just… so where is it? Where do you look for it?

At the moment Comet SWAN is a morning object, visible low in the NE before sunrise, to the lower left of the Square of Pegasus. In a week or so’s time it might be easier to find it after sunset, when it will still be low in the north, but for now here’s where to look for it tomorrow morning, May 17th…

…and here’s where it will be until the middle of June:

Personally I’m pinning my hopes on my first view being around May 19th, in either the morning or evening sky or both. Here’s where it will be…

Now that Comet SWAN F8 is being seen – or at least photographed – in northern skies, a word of caution for members who might not be sure what to look for and have high expectations.

When SWAN was putting on its show in the southern sky some amazing photos of it were taken and shared online. Will it look that good in the northern sky? We don’t know. But don’t expect it to look anything like its photos when you see it in the sky. Those photos are taken by experienced amateur astronomers who use very sophisticated photographic and astronomical equipment to take images, which are then processed using computer software, to make them look like they do. They are absolutely fantastic, but they can give beginners the wrong impression and lead them to believe that they are going to see the comet in the photo – big, bright, long tail, streamers flapping everywhere – in the sky with their own eyes. We wish…!

Here is a pic I made to show the difference. On the left: what many beginners I’ve met and spoken to expect to see in the sky. On the right: how big a comet in a photo like that would usually be in the sky.

Hopefully Comet SWAN will be bigger than that in the sky tho…

It’s also important to remember that although astronomers’ posts and charts show and talk about the comet “moving across the sky” that movement is not apparent as you look at it. Comets move slowly across the sky, moving a little way along their track night after night. (sometimes they can shift position quite a lot from night to night, but only if they’re coming close to Earth). So you will not see Comet SWAN “go over” like an airplane or a shooting star. It will be in one position for a morning, or an evening, and then will have moved on a bit the next morning or evening.

So, with all that in mind, good luck to everyone who’s now going to be going out looking for Comet SWAN over the next couple of weeks. Let us know what you see!

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