Daily Sunspot Evaluation
Observation Sheet Wednesday, 20 February 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)
- 9
- Number of spots (f)
- 48
- Relative number (R)
- 138
- Observer
- AK
- Reading
- all checks consistent
- File
- 19570220.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | A – 1 | 15 | 29E | ||||
| 2 | C – 3 | -14 | 49E | ||||
| 3 | H – 5 | -27 | 8E | ||||
| 4 | E – 28 | -22 | 13W | ||||
| 5 | A – 1 | -10 | 62W | ||||
| 6 | A – 2 | 9 | 31W | ||||
| 7 | J – 1 | 16 | 27W | ||||
| 8 | B – 5 | 8 | 14W | ||||
| 9 | A – 2 | 13 | 17W |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.