Solar Rotation Nos: 2224 to 2225
Very quiet. The combination of low Sun in the sky and cloudy weather had an adverse effect on the number of observations received for December.
Here are the solar highlights for December 2019 together with a selection of images.
Sunspots
Just two Active Region in December. The rest of the month the Sun was spotless.
AR2753 appeared on the 24th at the high southern latitude of -29° as a tiny Bxo type sunspot. This meant it was a new Sunspot Cycle (No. 25). It lasted until the 25th but was gone by the 26th.
AR2754 also appeared on the 24th but at the high northern latitude of +24°. This too was a Bxo type sunspot and a new Sunspot Cycle sunspot. It too lasted a couple of days but was gone by the 26th.
SPA Sunspot Mean Daily Frequency: 0.06 (was 0.02).
SPA Relative Sunspot Number: 0.56 (was 0.20).
Solar Prominences, Plage, Filaments and Flares
The generally poor weather also took its toll with the number of observations this month. There were few prominences, notably some small but bright prominences on the 1st and two detached prominences on the 3rd.
Images of AR2753 and AR2754 in Hydrogen-alpha were captured by Carl Bowron on Christmas Day and some faint prominences were also seen that day.
No filaments were reported but there was a bright area of plage seen near the NW limb on the 16th.
SPA Prominence Mean Daily Frequency (MDF): 1.20 (was 0.73).
Well done to Brian Gordon-States who observed 25 days, Jonathan Shanklin on 24 days and Alan Heath on 21 days.
Detailed count records of Active Regions and Relative Sunspot Numbers came from: Brian Gordon-States, Michael Fullerton, Alan Heath, Ian Lee, and Lee Macdonald.
Images and drawings were supplied by: Carl Bowron, Ian Lee and Cliff Meredith.