Daily Sunspot Evaluation
Observation Sheet Friday, 13 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)
- 52
- Relative number (R)
- 92
- Observer
- MH
- Reading
- all checks consistent
- File
- 19510413.jpg
Sunspot groups
| No | Group (class – spots) | r | p | Margin no. |
|---|---|---|---|---|
| 1 | E – 21 | 0.94 | 47 | |
| 2 | D – 16 | 0.8 | 67 | |
| 3 | D – 13 | 0.62 | 234 | |
| 4 | A – 2 | 0.93 | 235 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.