Daily Sunspot Evaluation
Observation Sheet Thursday, 9 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)
- 9
- Number of spots (f)
- 79
- Relative number (R)
- 169
- Observer
- TÖ
- Reading
- all checks consistent
- File
- 19810409.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | HAX – 1 | 18 | 47W | 347 | 50W | 2.5 | |
| 2 | BRC – 18 | 5 | 34W | 336 | 39W | 11.25 | |
| 3 | AXX – 3 | 8 | 23W | 323 | 26W | 2 | |
| 4 | DBI – 10 | 8 | 17W | 317 | 20W | 8 | |
| 5 | DKC – 11 | 9 | 07W | 307 | 10W | 10 | |
| 6 | EKC – 28 | 19 | 13E | 287 | 10E | 17.5 | |
| 7 | AKX – 1 | 20 | 53E | 247 | 50E | 1 | |
| 8 | DAX – 4 | 14 | 66E | 234 | 63E | 12 | |
| 9 | BXO – 3 | -7 | 66W | 6 | 63W | 6 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.