Daily Sunspot Evaluation
Observation Sheet Tuesday, 28 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)
- 5
- Number of spots (f)
- 29
- Relative number (R)
- 79
- Observer
- SM
- Reading
- all checks consistent
- File
- 19810428.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | HAX – 5 | 15 | 18E | 32 | 14E | 2.5 | |
| 2 | CAO – 17 | 3 | 26E | 24 | 22E | 13 | |
| 3 | AXX – 1 | 4 | 66E | 344 | 62E | ||
| 4 | HAX – 1 | 20 | 70E | 340 | 66E | 25 | |
| 5 | BXI – 5 | -15 | 33E | 17 | 29E | 4 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.