Daily Sunspot Evaluation
Observation Sheet Thursday, 21 September 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)
- 5
- Number of spots (f)
- 37
- Relative number (R)
- 87
- Observer
- FA
- Reading
- all checks consistent
- File
- 19720921.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | ? – 14 | -6 | 71E | 31 | |||
| 2 | J – 5 | -16 | 23E | 79 | |||
| 3 | B – 9 | -11 | 13W | 115 | |||
| 4 | A – 1 | -9 | 65W | 167 | |||
| 5 | B – 8 | 7 | 51W | 153 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.