NLN Aurora Briefs – October 21, 2015

Aurora Brief Number 2 of 14
Previous Brief: NLN Aurora Briefs – October 20, 2015
Next Brief: NLN Aurora Briefs – October 22, 2015

Flare activity was relatively quiet over the past 24 hours with just four flares and only three passing the C-class threshold. Active region 2436 decreased in size by a small amount but developed a delta spot and is now classified Beta-Delta. Active regions with Delta spots are more likely to produce flaring, so keep an eye on this over the next 24-48 hours.

Delta spot in AR2436
AR2436 now has a delta spot in the region

There were two notable instances of filament activity as well. A small filament just to the north and west of AR2434 showed a short burst of activity from 02:00 to 04:00. The second instance was a much larger filament eruption along a NE/SW line with AR2424 at the south west end. We’ve marked the filament in the first image. In the second image, watch as the eruption starts in the NE portion of the filament, then follows about 3/4 the length of the like a lightning strike. If this produced a CME, confirmation will be in the LASCO imagery over the next 24 hours. Tomorrow’s Aurora Brief will recap for sure.

Large Filament
Large filament identified with arrows from AIA 171 imagery

And in motion:

Animated GIF of filament eruption
Animated GIF Showing Filament Eruption from Oct 20, 2015

2003 on The Sun:

Active Region was quieter than the previous day’s X-class flare, but continued to grow and maintained it’s delta structure. Geomagnetic activity is expected to reach storm levels each of the next three days due to a Coronal Hole and the CME from the X-class flare

Happy Hunting