Daily Sunspot Evaluation
Observation Sheet Saturday, 20 December 1969
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)
- 8
- Number of spots (f)
- 55
- Relative number (R)
- 135
- Observer
- AT
- Reading
- all checks consistent
- File
- 19691220.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | D – 3 | 11 | 51°E | 8 | |||
| 2 | J – 7 | -13 | 53°E | 6 | |||
| 3 | C – 10 | -12 | 04°W | 63 | |||
| 4 | A – 2 | -28 | 34°W | 33 | |||
| 5 | C – 14 | -13 | 32°W | 31 | |||
| 6 | A – 2 | 6 | 31°W | 90 | |||
| 7 | J – 1 | 11 | 21°W | 80 | |||
| 8 | D – 16 | 12 | 03°W | 62 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.