Daily Sunspot Evaluation
Observation Sheet Friday, 21 September 1973
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)
- 6
- Number of spots (f)
- 17
- Relative number (R)
- 77
- Observer
- HM
- Reading
- all checks consistent
- File
- 19730921.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | A – 1 | 18 | 01E | 323 | 174 | ||
| 2 | D – 5 | 14 | 70E | 254 | 175 | ||
| 3 | J – 2 | 5 | 65E | 259 | 176 | ||
| 4 | A – 4 | 4 | 41E | 283 | 179 | ||
| 5 | A – 4 | -13 | 07W | 331 | 480 | ||
| 6 | J – 1 | 14 | 04W | 328 | 170 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.