Daily Sunspot Evaluation
Observation Sheet Friday, 17 August 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)
- 22
- Relative number (R)
- 52
- Observer
- ET
- Reading
- all checks consistent
- File
- 19510817.jpg
Sunspot groups
| No | Group (class – spots) | r | p | Margin no. |
|---|---|---|---|---|
| 1 | C – 9 | 0.82 | 134 | |
| 2 | C – 11 | 0.54 | 156 | |
| 3 | J – 2 | 0.82 | 268 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.