Daily Sunspot Evaluation
Observation Sheet Wednesday, 18 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)
- 104
- Relative number (R)
- 214
- Observer
- HÇ0
- Reading
- all checks consistent
- File
- 19910918.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | HA – 6 | 2 | 03W | 359 | 06W | 2.5 | 502 |
| 2 | BXO – 3 | 15 | 07E | 349 | 04E | 3 | 517 |
| 3 | EKO – 38 | 8 | 13E | 343 | 10E | 10.5 | 505E |
| 4 | BXO – 6 | 8 | 23E | 333 | 20E | 7.5 | 520 |
| 5 | AX – 5 | 9 | 54E | 302 | 51E | 3 | 521 |
| 6 | BXO – 5 | -19 | 38W | 34 | 41 | 3 | 522 |
| 7 | AX – 15 | -22 | 33W | 29 | 36W | 3.5 | 500 |
| 8 | AX – 1 | -17 | 25W | 21 | 28W | - | 523 |
| 9 | HA – 4 | -11 | 18W | 14 | 21W | 6 | 501 |
| 10 | BXI – 19 | -12 | 05W | 1 | 08W | 9 | 518 |
| 11 | AX – 2 | -20 | 25E | 331 | 22E | 1 | 519 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.