Statistics of sunspot activity
September, 1987
Visual indices of solar activity by National Geophysical Data Center
| Date | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | Average | % |
| W | 37.14 | 37.50 | 40.14 | 45.14 | 42.43 | 45.38 | 59.83 | 71.83 | 77.29 | 63.14 | 61.86 | 49.71 | 33.00 | 20.17 | 21.00 | 16.00 | 27.20 | 32.29 | 41.43 | 45.17 | 33.86 | 24.17 | 31.50 | 30.14 | 11.50 | 13.17 | 19.17 | 24.00 | 34.83 | 31.60 | 37.39 | 100 |
| Wn | 0.00 | 0.00 | 0.00 | 0.00 | 5.00 | 0.00 | 0.00 | 11.50 | 12.71 | 10.00 | 12.43 | 9.57 | 3.14 | 0.00 | 4.17 | 1.57 | 11.00 | 9.43 | 11.00 | 12.67 | 11.00 | 9.50 | 11.17 | 11.14 | 11.50 | 13.17 | 11.00 | 12.75 | 20.67 | 16.20 | 8.08 | 21.60 |
| Ws | 37.14 | 37.50 | 40.14 | 45.14 | 37.43 | 45.38 | 59.83 | 60.33 | 64.57 | 53.14 | 49.43 | 40.14 | 29.86 | 20.17 | 16.83 | 14.43 | 16.20 | 22.86 | 30.43 | 32.50 | 22.86 | 14.67 | 20.33 | 19.00 | 0.00 | 0.00 | 8.17 | 11.25 | 14.17 | 15.40 | 29.31 | 78.40 |
| n | 3.14 | 2.63 | 2.00 | 2.00 | 2.14 | 2.25 | 2.83 | 3.83 | 3.86 | 3.86 | 4.00 | 3.43 | 2.43 | 1.17 | 1.33 | 1.14 | 2.00 | 2.43 | 3.00 | 3.00 | 2.71 | 2.00 | 2.83 | 2.71 | 1.00 | 1.17 | 1.67 | 2.13 | 2.67 | 2.00 | 2.45 | 100 |
| A | 0.71 | 1.25 | 0.71 | 0.57 | 0.86 | 1.13 | 0.67 | 1.83 | 1.00 | 0.86 | 0.71 | 1.14 | 1.14 | 0.17 | 0.00 | 0.14 | 0.00 | 0.00 | 0.14 | 0.00 | 0.14 | 0.33 | 0.83 | 1.00 | 0.00 | 0.00 | 0.33 | 1.75 | 0.83 | 0.00 | 0.61 | 24.90 |
| B | 1.14 | 0.38 | 0.00 | 0.29 | 0.43 | 0.00 | 0.00 | 0.50 | 0.29 | 0.57 | 0.86 | 0.43 | 0.00 | 0.00 | 0.33 | 0.00 | 0.00 | 0.57 | 1.14 | 0.83 | 0.57 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.33 | 0.38 | 0.67 | 0.80 | 0.35 | 14.32 |
| C | 0.29 | 0.13 | 0.00 | 0.14 | 0.14 | 0.00 | 0.17 | 0.50 | 1.14 | 0.43 | 0.86 | 1.00 | 1.14 | 1.00 | 1.00 | 0.86 | 1.00 | 0.86 | 0.71 | 1.50 | 0.43 | 0.67 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.83 | 1.20 | 0.53 | 21.80 |
| D | 0.00 | 0.13 | 0.29 | 0.00 | 0.00 | 0.13 | 0.17 | 0.00 | 0.00 | 0.14 | 0.14 | 0.14 | 0.14 | 0.00 | 0.00 | 0.14 | 0.00 | 0.00 | 0.00 | 0.50 | 0.57 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.08 | 3.39 |
| E | 0.00 | 0.00 | 0.57 | 0.43 | 0.43 | 0.38 | 0.83 | 0.83 | 1.00 | 0.43 | 0.14 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.17 | 6.87 |
| F | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| G | 0.00 | 0.63 | 0.14 | 0.57 | 0.29 | 0.38 | 0.00 | 0.00 | 0.00 | 0.43 | 0.71 | 0.57 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.12 | 5.06 |
| H | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.14 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.19 |
| I | 1.00 | 0.13 | 0.29 | 0.00 | 0.00 | 0.25 | 1.00 | 0.17 | 0.43 | 0.86 | 0.57 | 0.14 | 0.00 | 0.00 | 0.00 | 0.00 | 1.00 | 1.00 | 1.00 | 0.17 | 1.00 | 1.00 | 2.00 | 1.71 | 1.00 | 1.17 | 1.00 | 0.00 | 0.33 | 0.00 | 0.57 | 23.46 |
| x | 1.86 | 1.63 | 0.71 | 0.86 | 1.29 | 1.13 | 0.67 | 2.33 | 1.29 | 1.43 | 1.57 | 1.57 | 1.14 | 0.17 | 0.33 | 0.14 | 0.00 | 0.57 | 1.29 | 0.83 | 0.71 | 0.33 | 0.83 | 1.00 | 0.00 | 0.00 | 0.67 | 2.13 | 1.50 | 0.80 | 0.96 | 39.22 |
| r | 0.57 | 0.13 | 0.14 | 0.00 | 0.00 | 0.00 | 0.17 | 0.50 | 0.86 | 0.00 | 0.29 | 0.29 | 0.00 | 0.17 | 0.00 | 0.00 | 0.00 | 0.14 | 0.29 | 0.17 | 0.29 | 0.00 | 0.17 | 0.00 | 0.17 | 0.17 | 0.33 | 0.00 | 0.00 | 0.00 | 0.16 | 6.56 |
| s | 0.43 | 0.38 | 0.43 | 0.57 | 0.14 | 0.63 | 1.00 | 0.17 | 0.71 | 1.29 | 1.43 | 0.86 | 0.86 | 0.50 | 0.83 | 1.00 | 1.80 | 1.14 | 1.14 | 1.50 | 1.57 | 1.33 | 1.67 | 1.57 | 0.67 | 0.50 | 0.50 | 0.00 | 0.67 | 0.80 | 0.87 | 35.55 |
| a | 0.29 | 0.50 | 0.71 | 0.57 | 0.71 | 0.50 | 0.17 | 0.00 | 0.29 | 1.00 | 0.71 | 0.71 | 0.29 | 0.33 | 0.17 | 0.00 | 0.20 | 0.57 | 0.29 | 0.50 | 0.14 | 0.33 | 0.17 | 0.14 | 0.17 | 0.50 | 0.17 | 0.00 | 0.50 | 0.40 | 0.37 | 15.03 |
| h | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.17 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.01 | 0.23 |
| k | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.67 | 0.83 | 0.71 | 0.14 | 0.00 | 0.00 | 0.14 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.08 | 3.41 |
| x | 1.71 | 1.38 | 1.00 | 0.57 | 0.86 | 1.38 | 1.67 | 2.00 | 1.43 | 1.86 | 1.29 | 1.29 | 1.14 | 0.17 | 0.00 | 0.14 | 1.00 | 1.00 | 1.14 | 0.17 | 1.14 | 1.33 | 2.83 | 2.71 | 1.00 | 1.17 | 1.33 | 1.75 | 1.17 | 0.00 | 1.19 | 48.56 |
| o | 1.43 | 1.25 | 0.29 | 0.86 | 0.71 | 0.38 | 0.17 | 1.00 | 1.43 | 1.29 | 2.29 | 2.00 | 1.14 | 1.00 | 1.33 | 1.00 | 1.00 | 1.43 | 1.86 | 2.50 | 1.57 | 0.67 | 0.00 | 0.00 | 0.00 | 0.00 | 0.33 | 0.38 | 1.50 | 1.80 | 1.02 | 41.69 |
| i | 0.00 | 0.00 | 0.71 | 0.57 | 0.57 | 0.50 | 1.00 | 0.67 | 1.00 | 0.71 | 0.43 | 0.14 | 0.14 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.33 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.20 | 0.23 | 9.52 |
| c | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.17 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.01 | 0.23 |
| CV | 11.86 | 20.63 | 26.29 | 26.71 | 19.43 | 24.75 | 55.33 | 47.67 | 53.43 | 43.29 | 38.57 | 27.43 | 20.43 | 9.17 | 11.17 | 13.14 | 20.40 | 18.00 | 17.71 | 29.83 | 26.43 | 16.67 | 19.33 | 17.71 | 8.50 | 9.17 | 8.50 | 2.50 | 13.17 | 13.80 | 22.37 | 100 |
| CVn | 0.00 | 0.00 | 0.00 | 0.00 | 0.57 | 0.00 | 0.00 | 1.83 | 6.86 | 3.14 | 1.71 | 0.86 | 0.29 | 0.00 | 0.67 | 0.14 | 10.00 | 8.14 | 9.57 | 10.83 | 10.00 | 8.33 | 9.50 | 9.57 | 8.50 | 9.17 | 7.50 | 1.25 | 9.00 | 10.60 | 4.60 | 20.57 |
| CVs | 11.86 | 20.63 | 26.29 | 26.71 | 18.86 | 24.75 | 55.33 | 45.83 | 46.57 | 40.14 | 36.86 | 26.57 | 20.14 | 9.17 | 10.50 | 13.00 | 10.40 | 9.86 | 8.14 | 19.00 | 16.43 | 8.33 | 9.83 | 8.14 | 0.00 | 0.00 | 1.00 | 1.25 | 4.17 | 3.20 | 17.77 | 79.43 |
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