Daily Sunspot Evaluation
Observation Sheet Thursday, 17 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)
- 12
- Number of spots (f)
- 79
- Relative number (R)
- 199
- Observer
- AÖ0
- Reading
- counts consistent, some coordinates doubtful
- File
- 19810917.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | DKF – 32 | 15 | 12W | 843 ⚠ | 16W | 10 | |
| 2 | OKO – 8 | 20 | 08W | 339 | 12W | 7.5 | |
| 3 | HOX – 2 | 9 | 39E | 292 | 35E | 2 | |
| 4 | AXX – 1 | 9 | 58E | 293 ⚠ | 54E | - | |
| 5 | EKC – 9 | 10 | 68E | 263 | 64E | 12 | |
| 6 | AXX – 1 | -10 | 76W | 47 | 80W | - | |
| 7 | AXX – 1 | -17 | 62W | 33 | 66W | - | |
| 8 | CAI – 8 | -18 | 28W | 359 | 32W | 6 | |
| 9 | AXX – 5 | -6 | 19E | 312 | 15E | 1 | |
| 10 | AXX – 1 | -17 | 21E | 310 | 17E | - | |
| 11 | DAO – 8 | -9 | 43E | 288 | 39E | 8 | |
| 12 | ? – 3 | -9 | 79E | 252 | 75E | ? |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.