Daily Sunspot Evaluation
Observation Sheet Thursday, 18 February 1971
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)
- 32
- Relative number (R)
- 92
- Observer
- SK
- Reading
- all checks consistent
- File
- 19710218.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | ? – 1 | -7 | 86E | 128 | |||
| 2 | C – 9 | -13 | 29E | 185 | |||
| 3 | E – 8 | -16 | 74E | 140 | |||
| 4 | J – 1 | -13 | 12E | 202 | |||
| 5 | H – 8 | 14 | 55W | 269 | |||
| 6 | G – 5 | 17 | 05W | 219 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.