Daily Sunspot Evaluation
Observation Sheet Friday, 13 September 1991
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)
- 11
- Number of spots (f)
- 113
- Relative number (R)
- 223
- Observer
- YK
- Reading
- all checks consistent
- File
- 19910913.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | DAI – 12 | 3 | 39W | 101 | 42W | 10 | 492 |
| 2 | BXI – 12 | 15 | 08E | 54 | 05E | 4 | 501 |
| 3 | HS – 1 | 2 | 65E | 357 | 62E | 2 | 502 |
| 4 | AX – 1 | 6 | 80E | 342 | 78E | - | 505 |
| 5 | DKI – 9 | -12 | 54W | 116 | 57W | 8.5 | 493 |
| 6 | HS – 1 | -24 | 38W | 100 | 41W | 2 | 492 |
| 7 | CAI – 26 | -21 | 17E | 45 | 14E | 7 | 499 |
| 8 | BRI – 47 | -21 | 33E | 29 | 30E | 18 | 500 |
| 9 | HS – 2 | -11 | 49E | 13 | 46E | 2 | 501 |
| 10 | AX – 1 | -12 | 65E | 357 | 62E | - | 506 |
| 11 | AX – 1 | -16 | 66E | 356 | 63E | - | 507 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.