Daily Sunspot Evaluation
Observation Sheet Thursday, 18 July 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)
- 7
- Number of spots (f)
- 42
- Relative number (R)
- 112
- Observer
- HE
- Reading
- all checks consistent
- File
- 19910718.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | HA – 1 | 21 | 44E | 51 | 44E | 1 | 381 |
| 2 | CAO – 3 | -24 | 70W | 165 | 73W | 12 | 358 |
| 3 | HA – 1 | -11 | 46W | 141 | 49W | 1 | 365 |
| 4 | BRO – 9 | -15 | 43W | 138 | 46W | 8.5 | 371 |
| 5 | BXO – 4 | -31 | 30W | 125 | 33W | 6 | 366 |
| 6 | HA – 10 | -26 | 09E | 86 | 06E | 5 | 378 |
| 7 | CAI – 14 | -22 | 30E | 65 | 27E | 8.5 | 360 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.