Daily Sunspot Evaluation
Observation Sheet Saturday, 13 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)
- 8
- Number of spots (f)
- 41
- Relative number (R)
- 121
- Observer
- WG
- Reading
- all checks consistent
- File
- 19570413.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | B – 6 | 12 | 26E | ||||
| 2 | A – 2 | 23 | 73E | ||||
| 3 | A – 2 | -25 | 63E | ||||
| 4 | E – 22 | -23 | 16W | ||||
| 5 | ? – 1 | -26 | 78W | ||||
| 6 | C – 4 | -20 | 53W | ||||
| 7 | A – 3 | 11 | 40W | ||||
| 8 | ? – 1 | 26 | 85W |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.