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  • Monty Leventhal OAM

Solar observations for December 2017

The lack of solar activity over December and months prior brings a question to the writers mind. Are we heading for another Maunder minimum, bearing in mind the extreme cold conditions in the U.S.A. at present? I think not. The next 4 years might tell. Nonetheless I observe the Sun every day and there have been a few notable events.

My first observation was made on the 2nd December and once again the solar disc was completely clear of Sunspots and remained so until the 11th. A small group of 3 very small spots were observed with a Classification Value (CV) of Bxi (3) in Active Region (AR) 12691. By the following day they had completely disappeared and once again the Sun remained clear of all Sunspots until the 21st.

On that day a group of spots were observed in AR12692 with a CV of Dsi (28). By the 22nd it had grown to a CV of Esi (29) and on the 23rd it had grown in size to a CV of Dki (39). On the 26th of December only 2 very small spots could be seen in AR12692 giving it a CV of Bxi (3).

From the 26th the solar disc remained clear of Sunspots for the remainder of the month.


Prominence activity remained constant, though mostly faint. On the 2nd an active Single Arch Prominence on the NW limb reached an approximate height of 47,000 km and stretched across the limb for about 149,000km.

Another Unconnected Arch Prominence on the 10th reached an approximate height of 65,000 on the SE limb.

For the rest of the month most Prominences remained small and faint except for a Column type Prominence on the 31st which reached a height of about 84,000km.

Prominences were seen on all observing days this month but as mentioned, most were small and faint.


No Flares were seen for the whole month of observations.

For the month of December 2017 all Sunspot activity once again on the Sun remained extremely low.

A total of 17 Observations were made for the month with the remaining 14 days being cloud covered and/or rain.

A total of only 3 groups were observed. This included 2 groups in the north and 1 in the south, comprising of 11 spots in the north and 3 in the south giving a total of 14 Sunspots.

This is now a slight increase in the Sunspot count but no increase in the total of Sunspot groups.

The average Relevant Sunspot number for the month was 5 and the average CV was 6.4 and the Q CV 1

Most Prominences observed once again were quiet faint.

No CMEs were observed.

Monty Leventhal OAM.

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