Daily Sunspot Evaluation
Observation Sheet Monday, 13 April 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)
- 93
- Relative number (R)
- 213
- Observer
- TÖ
- Reading
- counts consistent, some coordinates doubtful
- File
- 19810413.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | HAX – 1 | 9 | 77W | 321 | 77W | 3 | |
| 2 | HAX – 1 | 15 | 66W | 310 | 66W | - | |
| 3 | EKC – 9 | 8 | 62W | 306 | 62W | 17 | |
| 4 | HAX – 1 | 18 | 60W | 304 | 60W | 0.5 | |
| 5 | EKC – 16 | 17 | 46W | 270 ⚠ | 46W | 17.5 | |
| 6 | ARX – 1 | 21 | 04W | 248 | 04W | - | |
| 7 | EKC – 25 | 14 | 12E | 232 | 12E | 15 | |
| 8 | DKE – 18 | 10 | 25E | 217 | 25E | 10 | |
| 9 | CAO – 3 | 23 | 72E | 172 | 72E | 6.5 | |
| 10 | BXO – 2 | -4 | 10E | 234 | 10E | 15 | |
| 11 | CAO – 5 | -5 | 26E | 218 | 26E | 4 | |
| 12 | CAI – 11 | -8 | 55E | 189 | 55E | 7 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.