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Table 1 Sunspot groups with maximum area of more than 3000 MSH and expected and observed maximum SXR flare class between 1879 and 2016 in the DHO catalog

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 1946/07/29 4720 X71.8 14,585 NA
5 1947/03/12 4554 X68.0 14,851 NA
6 2014/10/24 4419 X65.0 12,192 X2.0 (4)
7 1989/03/14 4201 X60.3 5395 X15 (11)
8 1990/11/16 3872 X53.3 6368 M7.5 (0)
9 1938/01/21 3627 X48.4 12,673 NA
10 1926/01/20 3619 X48.2 9861 NA
11 1917/02/13 3467 X45.2 7977 NA
12 2003/11/01 3388 X43.7 10,486 X28 (7)
13 2001/03/29 3387 X43.6 9393 X20 (3)
14 1937/10/05 3340 X42.7 12,553 NA
15 1905/02/02 3339 X42.7 5441 NA
16 1937/07/28 3303 X42.0 12,455 NA
17 1984/04/26 3274 X41.5 4474 X13 (3)
18 1991/03/23 3257 X41.1 6555 X9.4 (7)
19 1989/06/16 3249 X41.0 5528 M9.3 (0)
20 1991/10/27 3234 X40.7 6891 X6.1 (5)
21 1968/02/01 3202 X40.1 21,482 NA
22 1917/08/09 3178 X39.7 8181 NA
23 1982/07/11 3092 X38.1 3804 X9.8 (5)
24 1988/07/02 3047 X37.2 5060 M9.2 (0)
25 1892/02/10 3038 X37.1 2421 NA
26 1980/11/13 3030 X36.9 2779 X9.0 (4)
27 1938/10/12 3003 X36.4 13,024 NA
  1. NA: not available