Daily Sunspot Evaluation
Observation Sheet Saturday, 21 February 1981
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)
- 11
- Number of spots (f)
- 96
- Relative number (R)
- 206
- Observer
- GT
- Reading
- all checks consistent
- File
- 19810221.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | DAC – 9 | 19 | 68W | 266 | 70W | 8 | |
| 2 | DAC – 6 | 11 | 59W | 257 | 61W | 14.5 | |
| 3 | DAO – 5 | 14 | 38W | 236 | 40W | 10 | |
| 4 | AXX – 3 | 17 | 32W | 231 | 35W | 1 | |
| 5 | EKC – 48 | 11 | 01E | 197 | 01W | 10 | |
| 6 | HSX – 4 | 14 | 16E | 182 | 14E | 5 | |
| 7 | DAC – 11 | -6 | 63W | 261 | 65W | 10.5 | |
| 8 | AXX – 1 | -19 | 62W | 260 | 64W | 0.2 | |
| 9 | AXX – 2 | -24 | 04W | 202 | 06W | 0.9 | |
| 10 | AXX – 2 | -16 | 15E | 182 | 13E | 2.3 | |
| 11 | HAX – 5 | -17 | 66E | 132 | 64E | 4.4 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.