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Sunspot Activity Notes
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Sunspot Development
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The Sun as viewed from the Earth
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Sunspot numbers derived from individual drawings are shown below in the form of a colour table from blue through to red via green and yellow. A sunspot number of 0 is , a sunspot number of 50 is , a sunspot number of 100 is , a sunspot number of 150 is while a sunspot number of 200 or more is . The numbers are given for each solar rotation so that active longitudes can be identified. Dates can be seen by placing the mouse icon over each coloured square.

Rotation

                                                        

1918

                 13th January 1997 14th January 1997   16th January 1997         21st January 1997     24th January 1997 25th January 1997              

1919

     3rd February 1997   5th February 1997     8th February 1997 9th February 1997           15th February 1997     18th February 1997         23rd February 1997   25th February 1997      

1920

 1st March 1997 2nd March 1997       6th March 1997       10th March 1997 11th March 1997 12th March 1997 13th March 1997 14th March 1997 15th March 1997           21st March 1997 22nd March 1997     25th March 1997   27th March 1997  

1921

 28th March 1997 29th March 1997 30th March 1997 31st March 1997 1st April 1997 2nd April 1997 3rd April 1997 4th April 1997 5th April 1997 6th April 1997 7th April 1997 8th April 1997 9th April 1997 10th April 1997 11th April 1997 12th April 1997 13th April 1997 14th April 1997 15th April 1997 16th April 1997     19th April 1997 20th April 1997 21th April 1997 22nd April 1997 23rd April 1997  

1922

 24th April 1997       28th April 1997   30th April 1997 1st May 1997 2nd May 1997 3rd May 1997 4th May 1997 5th May 1997 6th May 1997 7th May 1997   9th May 1997 10th May 1997 11th May 1997 12th May 1997 13th May 1997                

1923

       25th May 1997 26th May 1997 27th May 1997 28th May 1997 29th May 1997 30th May 1997 31st May 1997               8th June 1997 9th June 1997 10th June 1997   12th June 1997 13th June 1997   15th June 1997 16th June 1997 17th June 1997  

1924

 18th June 1997   20th June 1997 21st June 1997 22nd June 1997           28th June 1997     1st July 1997 2nd July 1997 3rd July 1997   5th July 1997 6th July 1997 7th July 1997 8th July 1997 9th July 1997 10th July 1997 11th July 1997 12th July 1997 13th July 1997 14th July 1997  

1925

 15th July 1997 16th July 1997   18th July 1997 19th July 1997 20th July 1997 21st July 1997 22nd July 1997 23rd July 1997 24th July 1997 25th July 1997 26th July 1997 27th July 1997 28th July 1997 29th July 1997 30th July 1997     2nd August 1997 3rd August 1997 4th August 1997 5th August 1997 6th August 1997 7th August 1997 8th August 1997 9th August 1997 10th August 1997  

1926

 11th August 1997   13th August 1997 14th August 1997 15th August 1997 16th August 1997 17th August 1997 18th August 1997 19th August 1997 20th August 1997 21st August 1997   23rd August 1997 24th August 1997 25th August 1997 26th August 1997 27th August 1997 28th August 1997 29th August 1997   31st August 1997   2nd September 1997   4th September 1997   6th September 1997  

1927

 7th September 1997 8th September 1997 9th September 1997 10th September 1997   12th September 1997 13th September 1997   15th September 1997 16th September 1997   18th September 1997   20th September 1997 21st September 1997 22nd September 1997 23rd September 1997     26th September 1997               4th October 1997

1928

   6th October 1997     9th October 1997 10th October 1997   12th October 1997           18th October 1997 19th October 1997   21st October 1997 22nd October 1997 23rd October 1997   25th October 1997 26th October 1997   28th October 1997 29th October 1997   31st October 1997  

1929

 1st November 1997 2nd November 1997   4th November 1997       8th November 1997     11th November 1997                     22nd November 1997 23rd November 1997       27th November 1997  

1930

 28th November 1997 29th November 1997             6th December 1997 7th December 1997     10th December 1997 11th December 1997 12th December 1997 13th December 1997 14th December 1997                      

1931

 26th December 1997 27th December 1997   29th December 1997   31st December 1997 1st January 1998   3rd January 1998   5th January 1998   7th January 1998   9th January 1998 10th January 1998       14th January 1998           20th January 1998 21st January 1998  

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Last updated on 22 December 2002.