Daily Sunspot Evaluation
Observation Sheet Tuesday, 7 April 1981
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)
- 47
- Relative number (R)
- 107
- Observer
- SM
- Reading
- all checks consistent
- File
- 19810407.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | HHX – 1 | 19 | 19W | 345 | 22W | 3 | |
| 2 | CSE – 9 | 6 | 07W | 333 | 10W | 8 | |
| 3 | HJX – 1 | 9 | 11E | 315 | 08E | 2 | |
| 4 | DKO – 12 | 10 | 25E | 301 | 22E | 15 | |
| 5 | EKC – 18 | 20 | 40E | 286 | 37E | 17 | |
| 6 | CAI – 6 | -6 | 39W | 5 | 42W | 35 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.