Daily Sunspot Evaluation
Observation Sheet Sunday, 21 September 1975
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)
- 11
- Relative number (R)
- 41
- Observer
- FA
- Reading
- counts consistent, some coordinates doubtful
- File
- 19750921.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | B – 3 | 6 | 25E | 25 | 22E | ||
| 2 | A – 1 | 3 | 40W | 80 ⚠ | 43W | ||
| 3 | B – 7 | 10 | 39W | 89 | 42W |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.