Astroblog: Class X17 Solar Fare

Thursday, September 08, 2005

Class X17 Solar Fare

Image GOES-12 X-ray image NOAA/SEC
Today an X17 class flare blasted out of the sun. X17!!! X class flares are rare enough, but an X17 is one of the strongest recorded flares. The blast caused a complete blackout of high frequency radio transmissions on the day lit side of Earth. Only a few solar flares each solar cycle (which are roughly 10 years long) exceed an X10 rating. So it was big (and rare)

The blast was not Earth directed, so don't expect anything from this one (although there might be some disturbance on the 9th as the edges brush past us, so Tasmanian's watch out). The culprit is probably sunspot group 798, which produced significant geomagnetic storms last month.
The group has been renamed 808, and if it continues to be active (a previous group fired of lots of flares when pointed away from us, and fell, silent when it rotated into view), we may be in for some more aurora. Group 808 will be in the best position between 11 and 18 September, unfortunately that is when the Moon is waxing towards full, so Moonlight might be a problem.

# posted by Ian Musgrave @ 11:03 pm