Daily Sunspot Evaluation
Observation Sheet Friday, 20 September 1974
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)
- 3
- Number of spots (f)
- 13
- Relative number (R)
- 43
- Observer
- FA
- Reading
- all checks consistent
- File
- 19740920.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | A – 1 | 10 | 12E | 189 | |||
| 2 | A – 4 | 9 | 21E | 180 | |||
| 3 | H – 8 | 9 | 68W | 269 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.