The Sun Online and solar activity. June 20, 2014

Six sunspot groups were reported by Catania today. Only three C-class flares took place during the past 24 hours, and all of them occurred in the Catania sunspot group 89 (that, together with the Catania sunspot group 90, constitutes the NOAA AR 2093). The strongest flare of this time interval was the C5.0 flare peaking today at 11:20 UT. The flare was accompanied by coronal dimmings and a post-eruption arcade indicating the eruption of a CME. However, no coronagraph data are available at the moment to confirm the CME occurrence. We expect further flaring activity on the C-level, mostly from this sunspot group, with an M-class flare being possible but not very likely. A partial halo CME was detected by  SOHO/LASCO on June 19, first appearing in the LASCO C2 field of view at 19:24 UT (first frame after a long data gap). The CME had the angular width of around 190 degrees and projected plane-of-the-sky speed of around 400 km/s. The CME was produced by the eruption of a filament to the north of the Catania sunspot groups 89 and 90 (together constituting the NOAA AR 2093), starting around 14:25 UT as seen by SDO/AIA. The eruption was also accompanied by coronal dimmings and a post-erution arcade. It was followed by a perhaps related C4.0 flare peaking at 19:24 UT in the Catania sunspot group 89. This flare was, in turn, accompanied by a narrow CME first appearing in the LASCO C2 field of view at 19:48 UT. This narrow CME is not expected to arrive at the Earth. An interplanetary disturbance associated with the  partial halo CME is expected to arrive at the Earth late on June 23 or early on June 24, most probably only with a glancing blow. It may result in active to perhaps minor storm geomagnetic conditions. The Earth is currently inside a slow (around 430 km/s) solar wind flow with slightly elevated (around 6 nT) interplanetary magnetic field magnitude. The geomagnetic conditions are quiet and are expected to remain so.

Equipment: Coronado 90 +  Imaging Source DMK  + LX75
Processing: Photoshop, Avistack 300 frames
Date: 06/20/14
Time UT: 16:00
Exposure 1/500 sec.

Observatory Sponli