Daily Sunspot Evaluation
Observation Sheet Wednesday, 18 April 1951
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)
- 4
- Number of spots (f)
- 99
- Relative number (R)
- 139
- Observer
- WG
- Reading
- all checks consistent
- File
- 19510418.jpg
Sunspot groups
| No | Group (class – spots) | r | p | Margin no. |
|---|---|---|---|---|
| 1 | A – 5 | 0.07 | 140 | |
| 2 | C – 8 | 0.25 | 245 | |
| 3 | B – 5 | 0.39 | 332 | |
| 4 | F – 81 | 0.28 | 348 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.