Daily Sunspot Evaluation
Observation Sheet Friday, 18 April 1980
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)
- 69
- Relative number (R)
- 159
- Observer
- TÖ
- Reading
- all checks consistent
- File
- 19800418.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | HSX – 1 | 18 | 28W | 347 | 31W | 0.75 | |
| 2 | DAC – 19 | 12 | 20W | 339 | 23W | 11 | |
| 3 | AXX – 1 | 21 | 09W | 328 | 12W | - | |
| 4 | HSX – 2 | -21 | 80W | 39 | 83W | 4 | |
| 5 | HSX – 2 | -30 | 65W | 24 | 68W | 4 | |
| 6 | EKO – 7 | -8 | 55W | 14 | 58W | 15 | |
| 7 | DSC – 17 | -28 | 20W | 339 | 23W | 8 | |
| 8 | DAI – 17 | -16 | 54E | 265 | 51E | 10.5 | |
| 9 | ? – 3 | -11 | 81E | 238 | 78E | 9 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.