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Tue, 05 Jan 2016 - ALERT: Comet PANSTARRS X1 IN OUTBURST...

If the sky is clear (stop laughing!) where you are tonight, or even if there are just gaps in the cloud, you have a chance to see something quite rare - an "outbursting" comet.

When Comet C/2013 X1 (which I'll just call X1 from now on to save time) was discovered back in December 2013 it was shining, if that's the right word, at magnitude 20. Since then it has brightened steadily, and a few days ago was shining at around magnitude 9.6, close to its expected magnitude of 10. However, last night observers reported it had suddenly brightened to magnitude 8. Now, that might not seem like a big deal - after all, it means X1 is still far too faint to be visible to the naked eye, and requires binoculars or a telescope to see it - but it is a dramatic jump in brightness in astronomical and cometary terms, and it has got comet watchers around the world very excited - and desperate for clear skies, so they can take a look at it themselves!

Why has X1 brightened like this? Well, something has physically happened to the comet, something probably quite dramatic and violent. Either it ran into something, way out there, and the impact released a lot of fresh cometary dust and gas, making it brighten, or something happened on the surface of the comet to reveal or liberate a lot of fresh material. Maybe an area of the surface collapsed, or a fissure opened up and a fresh jet spat out. We don't know. We can't know. All we can do is observe the comet whenever possible, and be grateful that it has brightened, giving us something exciting and interesting to look at.

So, where do you find this outbursting comet?

Luckily for those of us who have been left with sleep deprivation after looking at and photographing Comet  CATALINA in the pre-dawn sky over the past couple of months, X1 is an evening object, visible from sunset until late evening. It is currently lurking in the bottom left corner of the Square of Pegasus, which is high in the south after dark. As the chart below shows, you'll find it by looking to the right of the rising stars of Orion, and the Hyades and Pleiades clusters.



The second chart shows exactly where to look for the comet within the Square itself, after dark tonight...



The third chart shows how, for the next couple of weeks, X1 will appear to fall slowly through and then drop out of the Square of Pegasus...



...on its way out of the northen sky and into the southern, where it might... might... reach naked eye brightness. But before then, up here in the northern hemisphere we should grab any and every chance we get to see this comet because this brightening will not last. As Neil Norman - who runs the popular Comet Watch Facebook group - says: "This outburst will probably gradually fade by perhaps a whole magnitude within a couple of weeks."

With that in mind, comet watchers around the world are scrabbling to centre X1 in their telescope eyepieces and camera viewfinders. One of them, Kos Coronaios, has been observing and photographing X1 from his farm just outside the small town of Louis Trichardt in Limpopo Province, South Africa and he has generously sent me two if his latest images of X1 to share with SPA members. Here they are - if you're interested in the equipment and settings Kos used, enlarge the images by clicking on them and you'll see details at the bottom.





In an email Kos told me: "It's summer time down here, which is also our rainy season. The forecast for the evening was clear skies and after confirming that the comet would be visible, I set up shortly after sunset. I had to find a clear view towards the north-west and this meant having to carry equipment to the bottom corner of the garden about 50 meters away. The telescope I normally use is an 8-inch Meade SCT, on which I piggy-back a Canon 60D and 300mm lens. After aligning the telescope and mounting the camera I slewed it at the target area and was surprised to spot the comet easily in the 26mm eyepiece. Estimating the magnitude at around +7.5 and DC 3, I picked up a pair of binoculars (12x50), and after a brief delay managed to acquire the comet. With only about an hour or so before X1 moved too close to the horizon I wanted to start the imaging session as quickly as possible. Once the camera is taking light frames the telescope cannot be touched as any vibration will spoil that particular frame, thus visual observation through the eyepiece cannot be done. I took about 40 thirty second light frames and around 30 darks, with DeepSkyStacker finally using only 21 light frames. The two images are the results of that photography session on the 4th January 2016."

I'm very grateful to Kos for sharing those images with us, Kos. I'm sure that having seen them, many Comet Section members and SPA members will now be scanning the Square of Pegasus wth binoculars and telescopes as soon as they get a chance.

Let us know how you get on!


Added by: Stuart Atkinson