Daily Sunspot Evaluation
Observation Sheet Friday, 17 July 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)
- 11
- Number of spots (f)
- 135
- Relative number (R)
- 245
- Observer
- AÖ0
- Reading
- all checks consistent
- File
- 19810717.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | ARX – 2 | 24 | 51W | 124 | 54W | 1 | |
| 2 | DAO – 10 | 25 | 39W | 109 | 42W | 15 | |
| 3 | DAO – 4 | 7 | 03W | 73 | 06W | 4 | |
| 4 | CAI – 7 | 17 | 22E | 48 | 19E | 45 | |
| 5 | ARX – 3 | 16 | 54E | 16 | 51E | 2 | |
| 6 | HKX – 1 | 10 | 63E | 7 | 60E | 3 | |
| 7 | AXX – 1 | 16 | 65E | 5 | 62E | - | |
| 8 | EKC – 68 | -8 | 33W | 103 | 36W | 22 | |
| 9 | HKC – 16 | -28 | 30W | 100 | 33W | 6 | |
| 10 | CAI – 19 | -10 | 22E | 48 | 19E | 9 | |
| 11 | ARX – 4 | -19 | 34E | 36 | 31E | 15 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.