Daily Sunspot Evaluation
Observation Sheet Sunday, 28 April 1957
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)
- 11
- Number of spots (f)
- 55
- Relative number (R)
- 165
- Observer
- MH
- Reading
- all checks consistent
- File
- 19570428.jpg
Sunspot groups
| No | Group (class – spots) | r | p | Margin no. |
|---|---|---|---|---|
| 1 | A – 1 | 16 | 28 | |
| 2 | J – 1 | 25 | 49 | |
| 3 | A – 1 | 22 | 58 | |
| 4 | A – 1 | 25 | 75 | |
| 5 | D – 17 | -4 | 28 | |
| 6 | J – 2 | -11 | 24 | |
| 7 | A – 4 | -21 | 16 | |
| 8 | A – 2 | -28 | 1 | |
| 9 | D – 14 | -17 | 4 | |
| 10 | D – 10 | -9 | 7 | |
| 11 | J – 2 | -15 | 52 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.