Daily Sunspot Evaluation
Observation Sheet Friday, 18 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)
- 11
- Number of spots (f)
- 67
- Relative number (R)
- 177
- Observer
- HM
- Reading
- counts consistent, some coordinates doubtful
- File
- 19810918.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | DKI – 13 | 15 | 25W | 243 ⚠ | 28W | 11 | |
| 2 | CKI – 5 | 19 | 21W | 339 | 24W | 48 | |
| 3 | DAO – 4 | 19 | 07W | 325 | 10W | 3 | |
| 4 | BXI – 9 | 13 | 10E | 308 | 07E | 4 | |
| 5 | HXX – 1 | 9 | 26E | 292 | 23E | 4 | |
| 6 | EKE – 16 | 9 | 54E | 264 | 51E | 1 | |
| 7 | AXX – 2 | 16 | 45W | 3 | 49W | - | |
| 8 | AXX – 1 | 6 | 07W | 325 | 10W | - | |
| 9 | ARX – 7 | 4 | 04E | 322 ⚠ | 01E | 2 | |
| 10 | BXO – 2 | 9 | 27E | 291 | 24E | 1 | |
| 11 | DKC – 7 | 9 | 67E | 251 | 64E | 1 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.