Sunday 12 January 2014

AR11944 - the Bringer of Aurora? 11th January

ar11944-wl-colour by Mark Townley
ar11944-wl-colour, a photo by Mark Townley on Flickr.

There has been much talk this week of aurora visible here in the UK, well this picture shows the culprit that is the origin of all these rumours: AR11944, the huge sunspot group seen here on the limb of the sun in this photograph. At one point earlier this week the main spot was over 3 times the size of Earth, and the largest spot on the Sun in nearly a decade, it was even visible to the naked eye it was so large. The active region crackled with flares throughout the week sending a coronal mass ejection squarely towards Earth. A combination of social media and BBC stargazing live led the population of the UK to believe that aurora would be visible from the UK. This ended up materialising simply not to be true. It has to be a real 1 in 50 year auroral storm to be visible from the urban population centres of the UK, but as usual the media over inflated the chances of visibility. Yes, aurora are often visible from the northern coasts of Northern Ireland and Scotland, but this is due to the low horizon and the fact the view to the north is over 100's of miles of light pollution free Atlantic Ocean. In the towns, cities and countryside in most places in the UK the horizon is often obstructed due to trees and buildings etc, and then the sky is sullied with light pollution. Most of the time from the favourable locations in the UK the aurora is only visible as a low arc on the horizon with maybe some faint rays shooting up from this. It is only when you get directly underneath the auroral oval in places like Iceland and Lapland that the aurora becomes the bright all sky display that the media portrays. I have only seen the aurora twice in the UK; once some 30 years ago when light pollution was virtually non existent in rural locations, and back in 1999 when a huge storm descended over much of the northern hemisphere of our planet. These types of storms are very few and far between and require flaring from our star considerably larger than what we had this week. It's a shame the media don't portray these things accurately. Interestingly, as a result of this media conditioning, i've had several people say to me over the past couple of days how they saw the aurora in the UK; they didn't see the aurora, it wasn't visible here from the middle of England. Yes, they saw something they thought was the aurora, but because media said they should see it then they did... It's amazing the grip media has on people. Anyway, enough of my rant! I hope you like the picture, i'm glad I managed to photograph this spot before it disappeared over the limb. The shot was taken with the 70mm @ f12, DMK31, Lunt solar wedge, continuum filter and triband ERF.