Daily Sunspot Evaluation
Observation Sheet Sunday, 12 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)
- 3
- Number of spots (f)
- 10
- Relative number (R)
- 40
- Observer
- HA
- Reading
- all checks consistent
- File
- 19710912.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | J – 1 | 13 | 53°E | 319 | |||
| 2 | B – 8 | -16 | 11°E | 1 | |||
| 3 | ? – 1 | 17 | 82W | 94 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.