Daily Sunspot Evaluation
Observation Sheet Tuesday, 18 April 1972
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)
- 53
- Relative number (R)
- 113
- Observer
- HM
- Reading
- all checks consistent
- File
- 19720418.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | A – 1 | 8 | 50E | 315 | |||
| 2 | D – 8 | -6 | 02W | 7 | |||
| 3 | E – 37 | -10 | 41E | 324 | |||
| 4 | A – 4 | -16 | 17W | 22 | |||
| 5 | A – 1 | -10 | 54W | 59 | |||
| 6 | J – 2 | 8 | 23W | 28 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.