Daily Sunspot Evaluation
Observation Sheet Friday, 21 July 1972
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)
- 6
- Number of spots (f)
- 40
- Relative number (R)
- 100
- Observer
- SK
- Reading
- all checks consistent
- File
- 19720721.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | ? – 1 | 4 | 82E | 119 | |||
| 2 | B – 20 | -9 | 27W | 228 | |||
| 3 | H – 4 | -10 | 40W | 241 | |||
| 4 | ? – 1 | -13 | 73W | 274 | |||
| 5 | A – 5 | 9 | 44W | 245 | |||
| 6 | G – 9 | 14 | 32W | 233 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.