Daily Sunspot Evaluation
Observation Sheet Monday, 20 December 1971
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)
- 9
- Number of spots (f)
- 51
- Relative number (R)
- 141
- Observer
- FA
- Reading
- all checks consistent
- File
- 19711220.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | B – 2 | 8 | 04°E | 142 | |||
| 2 | A – 1 | -5 | 40°E | 106 | |||
| 3 | B – 6 | -10 | 60°E | 86 | |||
| 4 | J – 1 | -5 | 12°E | 134 | |||
| 5 | H – 10 | -16 | 51°E | 95 | |||
| 6 | E – 18 | -15 | 36°E | 110 | |||
| 7 | B – 5 | -10 | 29°W | 175 | |||
| 8 | G – 7 | 11 | 36°W | 182 | |||
| 9 | J – 1 | 17 | 51°W | 197 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.