Daily Sunspot Evaluation
Observation Sheet Thursday, 20 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)
- 5
- Number of spots (f)
- 35
- Relative number (R)
- 85
- Observer
- ED
- Reading
- all checks consistent
- File
- 19720420.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | H – 29 | -10 | 20E | 319 | |||
| 2 | A – 1 | -14 | 63E | 276 | |||
| 3 | A – 1 | -3 | 10E | 329 | |||
| 4 | A – 3 | -8 | 30W | 9 | |||
| 5 | J – 1 | 8 | 48W | 27 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.