Daily Sunspot Evaluation
Observation Sheet Thursday, 17 May 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)
- 10
- Number of spots (f)
- 139
- Relative number (R)
- 239
- Observer
- ET
- Reading
- all checks consistent
- File
- 19510517.jpg
Sunspot groups
| No | Group (class – spots) | r | p | Margin no. |
|---|---|---|---|---|
| 1 | C – 14 | 0.36 | 27 | |
| 2 | C – 5 | 0.9 | 45 | |
| 3 | A – 1 | 0.32 | 78 | |
| 4 | C – 11 | 0.88 | 84 | |
| 5 | J – 1 | 0.81 | 259 | |
| 6 | A – 1 | 0.65 | 263 | |
| 7 | A – 2 | 0.18 | 267 | |
| 8 | J – 4 | 0.26 | 281 | |
| 9 | F – 99 | 0.4 | 298 | |
| 10 | A – 1 | 0.55 | 299 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.