Daily Sunspot Evaluation
Observation Sheet Tuesday, 21 April 1964
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)
- 1
- Number of spots (f)
- 9
- Relative number (R)
- 19
- Observer
- SK
- Reading
- all checks consistent
- File
- 19640421.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | C – 9 | -8 | 23 | E |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.