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Table 2 Sunspot groups with maximum area of more than 3000 MSH and expected and observed maximum SXR flare class between 1879 and 2016 in the MA20 catalogue

From: Extremely large flares/multiple large flares expected from sunspot groups with large area

No. Date Maximum sunspot area (MSH) Expected maximum SXR flare class Region number Observed maximum SXR flare (number of X-class flares)
1 1947/04/08 6132 X106.3 14,886 NA
2 1946/02/07 5202 X83.1 14,417 NA
3 1951/05/19 4865 X75.1 16,763 NA
4 1989/03/16 4823 X74.1 5395 X15 (11)
5 1946/07/29 4720 X71.8 14,585 NA
6 1947/03/12 4554 X68.0 14,851 NA
7 2014/10/25 4534 X67.6 12,192 X2.0 (4)
8 1989/06/16 3753 X50.9 5528 M9.3 (0)
9 1938/01/21 3627 X48.4 12,673 NA
10 1926/01/20 3619 X48.2 9861 NA
11 2003/10/29 3486 X45.6 10,486 X28 (7)
12 1917/02/13 3467 X45.2 7977 NA
13 2001/03/30 3447 X44.8 9393 X20 (3)
14 1991/10/27 3428 X44.4 6891 X6.1 (5)
15 1937/10/05 3340 X42.7 12,553 NA
16 1905/02/02 3339 X42.7 5441 NA
17 1937/07/28 3303 X42.0 12,455 NA
18 1991/03/23 3233 X40.7 6555 X9.4 (7)
19 1988/07/01 3217 X40.4 5060 M9.2 (0)
20 1968/02/01 3202 X40.1 21,482 NA
21 1990/11/20 3179 X39.7 6368 M7.5 (0)
22 1917/08/09 3178 X39.7 8181 NA
23 1989/09/04 3098 X38.2 5669 X1.3 (3)
24 2000/09/23 3096 X38.1 9169 X1.2 (1)
25 1982/06/15 3039 X37.1 3776 X3.6 (5)
26 1892/02/10 3038 X37.1 2421 NA
27 1938/10/12 3003 X36.4 13,024 NA
  1. NA: not available