Daily Sunspot Evaluation
Observation Sheet Thursday, 16 September 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)
- 7
- Number of spots (f)
- 51
- Relative number (R)
- 121
- Observer
- HA
- Reading
- all checks consistent
- File
- 19710916.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | A – 1 | 3 | 52E | 267 | |||
| 2 | H – 4 | 4 | 40E | 279 | |||
| 3 | A – 1 | -3 | 80E | 239 | |||
| 4 | E – 26 | -12 | 43E | 276 | |||
| 5 | J – 5 | -13 | 52E | 267 | |||
| 6 | C – 13 | -15 | 42W | 1 | |||
| 7 | J – 1 | 12 | 00 | 319 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.