Daily Sunspot Evaluation
Observation Sheet Thursday, 19 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)
- 113
- Relative number (R)
- 153
- Observer
- ET
- Reading
- all checks consistent
- File
- 19510419.jpg
Sunspot groups
| No | Group (class – spots) | r | p | Margin no. |
|---|---|---|---|---|
| 1 | C – 1 | 0.2 | 224 | |
| 2 | C – 6 | 0.53 | 245 | |
| 3 | B – 5 | 0.46 | 303 | |
| 4 | F – 101 | 0.32 | 308 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.