Daily Sunspot Evaluation
Observation Sheet Thursday, 12 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)
- 9
- Number of spots (f)
- 89
- Relative number (R)
- 179
- Observer
- MB
- Reading
- all checks consistent
- File
- 19910912.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | DAI – 19 | 3 | 26W | 101 | 29W | 9 | 498 |
| 2 | ? – 1 | 2 | 77E | 358 | 74E | 3 | 582 |
| 3 | DAI – 13 | -12 | 41W | 116 | 44W | 8.5 | 493 |
| 4 | HS – 1 | -24 | 25W | 100 | 28W | 2 | 492 |
| 5 | AX – 1 | -6 | 12E | 63 | 09E | - | 496 |
| 6 | AX – 1 | -14 | 18E | 57 | 15E | - | 503 |
| 7 | CAI – 23 | -20 | 31E | 44 | 28E | 12 | 499 |
| 8 | BRI – 28 | -20 | 45E | 30 | 42E | 16 | 500 |
| 9 | HA – 2 | -11 | 63E | 12 | 60E | 5 | 501 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.