Daily Sunspot Evaluation
Observation Sheet Tuesday, 31 July 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)
- 7
- Number of spots (f)
- 40
- Relative number (R)
- 110
- Observer
- ET
- Reading
- all checks consistent
- File
- 19510731.jpg
Sunspot groups
| No | Group (class – spots) | r | p | Margin no. |
|---|---|---|---|---|
| 1 | A – 1 | 0.33 | 86 | |
| 2 | A – 3 | 0.43 | 90 | |
| 3 | C – 13 | 0.4 | 139 | |
| 4 | C – 17 | 0.41 | 253 | |
| 5 | A – 1 | 0.55 | 264 | |
| 6 | ? – 1 | 0.38 | 264 | |
| 7 | B – 4 | 0.76 | 267 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.