Daily Sunspot Evaluation
Observation Sheet Monday, 20 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)
- 13
- Number of spots (f)
- 70
- Relative number (R)
- 200
- Observer
- TÖ
- Reading
- all checks consistent
- File
- 19810420.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | ? – 3 | 14 | 77W | 231 | 79W | ||
| 2 | DAC – 6 | 10 | 70W | 224 | 72W | 10 | |
| 3 | DAO – 3 | 18 | 64W | 218 | 66W | 9 | |
| 4 | CAO – 3 | 14 | 55W | 209 | 57W | 8.5 | |
| 5 | HAX – 1 | 24 | 51W | 205 | 53W | 1.5 | |
| 6 | CAO – 3 | 23 | 22W | 176 | 24W | 5 | |
| 7 | CRO – 2 | 19 | 18W | 172 | 20W | 3 | |
| 8 | AXX – 1 | 13 | 12W | 166 | 14W | ||
| 9 | DAO – 3 | 8 | 02W | 156 | 04W | 5 | |
| 10 | DKC – 14 | 15 | 05E | 149 | 03E | 5 | |
| 11 | DAI – 9 | 25 | 08E | 146 | 06E | 10 | |
| 12 | DKC – 17 | -8 | 39W | 193 | 41W | 8 | |
| 13 | DAO – 5 | -10 | 11E | 143 | 09E | 9.5 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.