Daily Sunspot Evaluation
Observation Sheet Thursday, 20 April 1961
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)
- 6
- Number of spots (f)
- 9
- Relative number (R)
- 69
- Observer
- KA
- Reading
- all checks consistent
- File
- 19610420.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | H – 1 | 9 | 25E | ||||
| 2 | J – 1 | -9 | 37E | ||||
| 3 | A – 1 | -12 | 28E | ||||
| 4 | J – 1 | 3 | 41W | ||||
| 5 | B – 2 | 10 | 34W | ||||
| 6 | A – 3 | 15 | 54W |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.