Daily Sunspot Evaluation
Observation Sheet Saturday, 21 April 1973
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)
- 2
- Number of spots (f)
- 31
- Relative number (R)
- 51
- Observer
- ED
- Reading
- all checks consistent
- File
- 19730421.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | E – 18 | 11 | 38E | 150 | 68 | ||
| 2 | D – 13 | -16 | 05E | 183 | 69 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.