Solar Highlights for March 20

Solar Rotation Nos: 2228 to 2229

The Sunspot Mean Daily Frequency remained at the same level this month despite the appearance of two new sunspot cycle spots. Despite the very low level of sunspot activity the geomagnetic field of the Earth is still being buffeted by the solar wind, and this has sparked a few high latitude aurorae.

Here are the solar highlights for March 2020 together with a selection of images.

Sunspots

There were two very small Active Regions this month, both at high latitude. The rest of the month the Sun was spotless apart from south polar faculae reported on the south solar pole on the 25th.

2020 March 25 @1109UT South Polar Faculae. Image by Carl Bowron.

AR2758 comprising of 2 or 3 small spots appeared on the solar disc just slightly east of the Central Meridian at a high southern latitude of -29° on the 9th and 10th. At such a high latitude it was a new sunspot cycle (No. 25) sunspot. AR2758 was responsible for several strong shortwave radio bursts on the 8th.

AR2759 came into view over the east solar limb on the last day of March. At latitude +28° this was another Cycle 25 sunspot making an appearance.

SPA Sunspot Mean Daily Frequency: 0.06 (was 0.06)
SPA Relative Sunspot Number: 0.78 (was 0.83)

Solar Prominences, Plage, Filaments and Flares

There were a few but mostly small and occasionally bright prominences throughout the month.

A flame-like prominence was seen on the south limb on the 1st, this developed the following day into an arch-type and there were other smaller prominences around the rest of the solar limb. The arch had gone by the 3rd but there were still prominences mostly along the west limb.

2020 March 2 @1424UT Ha Prominence on SW limb. Image taken by Carl Bowron.
Two small but quite bright prominences were seen along the northwest limb on the 6th with a number of small spikes dotted around the rest of the limb on the same day.
2020 March 6 @1135UT Ha Prominence on the W limb. Image by Carl Bowron.
2020 March 6 @1129UT Ha Prominence on the E limb. Image by Carl Bowron.
A quite long detached prominence was seen just off the north west limb on the 12th.
The 16th saw prominences dotted around the limb but many were very low-lying in nature.
Another flame-like prominence was seen on the 20th but this time on the east limb.
Prominence activity picked up a bit from the 25th onwards particularly along the west limb and on the north and south limbs on the 30th.
Filaments were few and mostly faint but were nevertheless seen on the 5th, 6th, 13th, 23rd and 25th.
Bright areas of plage were seen on the 14th, 20th, 22nd and 30th.

No flares were reported.

SPA Prominence Mean Daily Frequency: 2.96 (was 1.22)

Well done to Brian Gordon-States who observed 28 days, to Jonathan Shanklin on 27 days and to Michael Fullerton on 25 days.

Detailed count records of Active Regions and Relative Sunspot Numbers came from: Brian Gordon-States, Michael Fullerton, Ian Lee, Lee Macdonald and Bob Steele.

Images and drawings were supplied by: Carl Bowron, Ian Lee and Cliff Meredith.