Daily Sunspot Evaluation
Observation Sheet Monday, 13 September 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)
- 5
- Number of spots (f)
- 19
- Relative number (R)
- 69
- Observer
- FA
- Reading
- all checks consistent
- File
- 19710913.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | J – 2 | 13 | 40E | 319 | |||
| 2 | A – 1 | 13 | 69E | 290 | |||
| 3 | ? – 1 | 4 | 80E | 279 | |||
| 4 | ? – 2 | -13 | 83E | 276 | |||
| 5 | C – 13 | -16 | 03W | 2 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.