Daily Sunspot Evaluation
Observation Sheet Sunday, 21 July 1957
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)
- 17
- Number of spots (f)
- 142
- Relative number (R)
- 312
- Observer
- YÖ
- Reading
- all checks consistent
- File
- 19570721.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | H – 7 | 27 | 42 | ||||
| 2 | H – 10 | 31 | 12E | ||||
| 3 | C – 8 | 32 | 35E | ||||
| 4 | A – 1 | 24 | 35E | ||||
| 5 | B – 2 | 21 | 31E | ||||
| 6 | E – 12 | 11 | 64E | ||||
| 7 | C – 15 | -22 | 22E | ||||
| 8 | C – 10 | -36 | 13E | ||||
| 9 | B – 4 | -38 | 21W | ||||
| 10 | C – 21 | -19 | 23W | ||||
| 11 | C – 15 | -9 | 19W | ||||
| 12 | A – 2 | -12 | 32W | ||||
| 13 | J – 1 | -18 | 52W | ||||
| 14 | B – 2 | -15 | 58W | ||||
| 15 | J – 2 | 15 | 26W | ||||
| 16 | B – 23 | 26 | 15W | ||||
| 17 | C – 7 | 24 | 5W |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.