Daily Sunspot Evaluation
Observation Sheet Sunday, 12 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)
- 13
- Number of spots (f)
- 112
- Relative number (R)
- 242
- Observer
- OG
- Reading
- all checks consistent
- File
- 19810412.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | ? – 4 | 5 | 76W | 336 | 79W | 10 | |
| 2 | AXX – 1 | 20 | 68W | 328 | 71W | ||
| 3 | FKC – 25 | 9 | 49W | 309 | 52W | 23 | |
| 4 | DSO – 2 | 16 | 47W | 307 | 50W | 6.25 | |
| 5 | EKC – 20 | 19 | 28W | 288 | 31W | 18.5 | |
| 6 | AXX – 1 | 17 | 17W | 277 | 20W | ||
| 7 | HAX – 2 | 21 | 13E | 247 | 10E | 1 | |
| 8 | FKC – 39 | 14 | 27E | 233 | 24E | 17 | |
| 9 | CAI – 12 | 9 | 42E | 218 | 39E | 7.5 | |
| 10 | AXX – 1 | 11 | 52E | 208 | 49E | ||
| 11 | AXX – 2 | -9 | 09E | 251 | 06E | ||
| 12 | CAO – 2 | -5 | 41E | 219 | 38E | 3.5 | |
| 13 | AXX – 1 | -17 | 67E | 193 | 64E |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.