Daily Sunspot Evaluation
Observation Sheet Friday, 13 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)
- 23
- Relative number (R)
- 93
- Observer
- MA
- Reading
- all checks consistent
- File
- 19710813.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | A – 1 | 22 | 05E | 43 | |||
| 2 | B – 2 | 14 | 12E | 36 | |||
| 3 | J – 2 | 13 | 55E | 353 | |||
| 4 | A – 1 | 10 | 43E | 5 | |||
| 5 | J – 5 | -12 | 40W | 88 | |||
| 6 | H – 10 | -7 | 51W | 99 | |||
| 7 | J – 2 | 12 | 78W | 126 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.