Daily Sunspot Evaluation
Observation Sheet Saturday, 21 August 1971
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)
- 6
- Number of spots (f)
- 80
- Relative number (R)
- 140
- Observer
- FA
- Reading
- all checks consistent
- File
- 19710821.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | B – 11 | 19 | 13E | 290 | |||
| 2 | G – 4 | -5 | 71E | 232 | |||
| 3 | F – 61 | -12 | 34E | 269 | |||
| 4 | J – 1 | -16 | 73W | 16 | |||
| 5 | A – 2 | 15 | 39W | 342 | |||
| 6 | H – 1 | 13 | 15W | 318 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.