Daily Sunspot Evaluation
Observation Sheet Thursday, 20 September 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)
- 4
- Number of spots (f)
- 10
- Relative number (R)
- 50
- Observer
- FA
- Reading
- all checks consistent
- File
- 19730920.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | C – 6 | 14 | 13E | 325 | 170 | ||
| 2 | ? – 1 | 13 | 81E | 257 | 175 | ||
| 3 | ? – 2 | 5 | 80E | 258 | 176 | ||
| 4 | A – 1 | -13 | 11W | 349 | 177 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.