Daily Sunspot Evaluation
Observation Sheet Saturday, 20 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)
- 10
- Number of spots (f)
- 53
- Relative number (R)
- 153
- Observer
- MB
- Reading
- all checks consistent
- File
- 19910720.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | HA – 3 | 21 | 19E | 48 | 16E | 2° | 381 |
| 2 | HA – 1 | -10 | 74W | 142 | 77W | 2 | 365 |
| 3 | DAI – 11 | -26 | 17W | 85 | 20W | 6 | 378 |
| 4 | CAI – 13 | -22 | 04E | 64 | 01E | 5.5 | 380 |
| 5 | CAI – 8 | -11 | 49E | 19 | 46E | 11 | 389 |
| 6 | HA – 1 | -5 | 60E | 8 | 57E | 2 | 380 |
| 7 | EKC – 6 | -16 | 73E | 355 | 70E | 12.5 | 391 |
| 8 | BRI – 4 | -26 | 51E | 17 | 48E | 4.5 | 392 |
| 9 | HA – 2 | 5 | 68E | 1 | 65E | 2 | 387 |
| 10 | DKC – 4 | 8 | 74E | 354 | 71E | 8.5 | 368 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.