Daily Sunspot Evaluation
Observation Sheet Wednesday, 18 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)
- 7
- Number of spots (f)
- 31
- Relative number (R)
- 101
- Observer
- FA
- Reading
- all checks consistent
- File
- 19710818.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | H – 1 | 13 | 25°E | 317 | |||
| 2 | J – 1 | 17 | 43°E | 293 | |||
| 3 | ? – 11 | -13 | 76°E | 266 | |||
| 4 | B – 14 | -15 | 33°W | 15 | |||
| 5 | A – 1 | 7 | 25°W | 7 | |||
| 6 | A – 1 | 14 | 12°W | 354 | |||
| 7 | J – 2 | 14 | 02°W | 344 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.