The Sun 9-5-09 - A Class Flare seen in CaK

Had to image in two separate sessions today due to intervening cloud and rain. Caught the Ha and CaK disks this morning at 11.30BST then imaged the active regions in more detail between 17.10 and 18.10 BST. The new AR is further round in the NE quarter now and the second can just be seen right on the limb. The first AR (nominally 11017 if it forms a sunspot) consists of two primary S- shaped strands of plage. While watching the active regions at 17.15 BST (16.15 UT) I noticed an area brightening rapidly in the plage. I dashed inside to confirm it was a flare on the GOES X-Ray flux monitor and it was peaking at A-Class, this was a first for me watching a flare brighten live! This second AR has been a hot bed of activity over the last 24 hours with many small eruptive prominences. The A-Class flare was subsequently confirmed by Thomas Ashcraft in Mexico who caught it as a radio burst at 16.14 UT.

Solar Radio Burst Image courtesy of Thomas Ashcraft, Mexico