Daily Sunspot Evaluation
Observation Sheet Monday, 21 April 1952
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)
- 5
- Number of spots (f)
- 31
- Relative number (R)
- 81
- Observer
- MH
- Reading
- all checks consistent
- File
- 19520421.jpg
Sunspot groups
| No | Group (class – spots) | r | p | Margin no. |
|---|---|---|---|---|
| 1 | ? – 1 | 0.47 | 48 | |
| 2 | B – 4 | 0.9 | 67 | |
| 3 | A – 1 | 0.33 | 86 | |
| 4 | D – 16 | 0.59 | 236 | |
| 5 | B – 9 | 0.29 | 293 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.