Daily Sunspot Evaluation
Observation Sheet Thursday, 21 February 1991
There is no typed record for this day. The values below were read by computer from the table on the sheet; when in doubt, see the drawing. Details →
- Number of groups (g)
- 12
- Number of spots (f)
- 134
- Relative number (R)
- 254
- Observer
- YK
- Reading
- all checks consistent
- File
- 19910221.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | HA – 2 | 22 | 46W | 282 | 48W | 1 | 64 |
| 2 | CAO – 15 | 30 | 09E | 227 | 07E | 8 | 77 |
| 3 | CAI – 8 | 42 | 50E | 186 | 48E | 9.5 | 86 |
| 4 | CAO – 3 | 17 | 63E | 173 | 61E | 6.5 | 91 |
| 5 | HA – 1 | -8 | 66W | 302 | 68W | 1 | 87 |
| 6 | DKC – 16 | -13 | 26W | 262 | 28W | 7 | 78 |
| 7 | AX – 4 | -18 | 19W | 255 | 21W | 1.5 | 76 |
| 8 | DAC – 26 | -16 | 05E | 231 | 03E | 8.5 | 79 |
| 9 | AR – 2 | -4 | 09E | 227 | 07E | 1.5 | 83 |
| 10 | FKO – 23 | -14 | 44E | 192 | 42E | 20 | 80 |
| 11 | AX – 5 | -9 | 42E | 194 | 40E | 3 | 68 |
| 12 | FKC – 29 | -21 | 42E | 194 | 40E | 13.5 | 90 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.