Daily Sunspot Evaluation
Observation Sheet Tuesday, 21 August 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)
- 11
- Relative number (R)
- 31
- Observer
- FY
- Reading
- all checks consistent
- File
- 19730821.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | B – 10 | 13 | 31E | 344 | 150 | ||
| 2 | A – 1 | 0 | 12E | 3 | 151 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.