I was in Brussels visiting the Royal Observatory Belgium to talk about improving the accuracy of the International Sunspot Number. The ISN i...

What an active region 12192 has been! Six X-class flares in 9 days. Here is an HMI image of AR 12192 at 1615 UTC on 23-Oct-2014. You can se...

An very nice animation of SDO images for the month of January 2014 is featured on the Astronomy Picture of the Day for March 12, 2014. The ...