Daily Sunspot Evaluation
Observation Sheet Wednesday, 21 July 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)
- 9
- Number of spots (f)
- 56
- Relative number (R)
- 146
- Observer
- HM
- Reading
- all checks consistent
- File
- 19710721.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | C – 7 | 15 | 15°E | 337 | |||
| 2 | A – 1 | 16 | 60°E | 292 | |||
| 3 | A – 2 | 12 | 46°E | 306 | |||
| 4 | E – 13 | 6 | 38°W | 30 | |||
| 5 | G – 9 | 9 | 25°W | 17 | |||
| 6 | J – 1 | 7 | 11°W | 3 | |||
| 7 | J – 1 | 15 | 72°W | 64 | |||
| 8 | B – 2 | 9 | 05°W | 357 | |||
| 9 | E – 20 | 13 | 01°W | 353 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.