Daily Sunspot Evaluation
Observation Sheet Tuesday, 17 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)
- 3
- Number of spots (f)
- 91
- Relative number (R)
- 121
- Observer
- MH
- Reading
- all checks consistent
- File
- 19510417.jpg
Sunspot groups
| No | Group (class – spots) | r | p | Margin no. |
|---|---|---|---|---|
| 1 | F – 75 | 0.4 | 15 | |
| 2 | C – 14 | 0.08 | 248 | |
| 3 | A – 2 | 0.44 | 353 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.