Daily Sunspot Evaluation
Observation Sheet Sunday, 13 September 1981
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)
- 8
- Number of spots (f)
- 71
- Relative number (R)
- 151
- Observer
- OG
- Reading
- counts consistent, some coordinates doubtful
- File
- 19810913.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | EKR – 42 | 9 | 42W | 65 | 44W | 14 | |
| 2 | HHK – 1 | 15 | 32W | 55 | 34W | 4.5 | |
| 3 | DAO – 2 | 10 | 31W | 54 | 33W | 4 | |
| 4 | OKS – 16 | 19 | 45E | 338 | 48E | 10.5 | |
| 5 | ? – 2 | -19 | 77W | 101 | 80W | 3 | |
| 6 | CAO – 6 | -19 | 14E | 9 | 12E | 7 | |
| 7 | HAX – 1 | -18 | 63E | 310 ⚠ | 61E | 3 | |
| 8 | ? – 1 | -5 | 70E | 267 ⚠ | 69E | 3 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.