I took this picture of the Sun with a small refractor and a solar filter earlier today. The giant sunspot group on the left has a dark core easily big enough to swallow the Earth. Astronomers have labelled it AR2192. At around 0500UT on Sunday AR2192 unleashed a powerful X-class flare. It wasn't Earth directed. The rotation of the Sun will carry AR2192 towards the solar meridian in a few days and any flares of that magnitude are very likely to create chances to see the aurora soon after that.
Adrian Jannetta writes...
Just back from a great public outreach session at Housesteads Roman Fort. The sky was beautiful and clear. The sky there seems BIG - with great visibility all the way to the horizon. The moon was out (waxing gibbous and bright) and that meant no Milky Way was visible. I bet that place is pitch black on a moonless night.
Here are some of the people who came to our event this evening. The stars of the Plough are in the sky behind them.
The second star from the end of the tail in The Plough - Mizar - is a double star. In times past it was known as the Horse and Rider - close inspection shows that Mizar has a faint companion. Appropriately enough the ability to resolve Mizar and Alcor may have constituted an eye test for Roman centurions, as it most certainly did for later Arabic fighters.
There was a decent turn out from NASTRO members with telescopes. I took my 10" Dobsonian and showed people the moon, Mizar and Alcor (double star in the Plough), the E.T. Cluster (NGC457), the Great Hercules Cluster (M13) the Pleiades (M45) and the Ring Nebula (M57).
Our events guy, Ian, has a lot of astronomy events like this lined up in the coming weeks and months. And they're free. There really is no excuse for not getting a great view of the sky through our telescopes :-)
Dr Adrian Jannetta FRAS
Amateur astronomer and mathematics teacher. Guitar strumming explorer of the universe!
Proud nerd and founder of the school space club. A young whippersnapper with a bucket-load of passion.