Daily Sunspot Evaluation
Observation Sheet Sunday, 21 April 1991
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)
- 9
- Number of spots (f)
- 46
- Relative number (R)
- 136
- Observer
- TÖ0
- Reading
- all checks consistent
- File
- 19910421.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | DAC – 15 | 8 | 65W | 245 | 68W | 9 | 159 |
| 2 | BXO – 4 | 15 | 44W | 224 | 47W | 4.5 | 120 |
| 3 | BXI – 7 | 13 | 36W | 216 | 39W | 6 | 169 |
| 4 | HA – 1 | -26 | 85W | 265 | 88W | 2.5 | 110 |
| 5 | BXI – 6 | -20 | 63W | 243 | 66W | 7 | 165 |
| 6 | CAI – 7 | -11 | 11W | 191 | 14W | 6 | 174 |
| 7 | AX – 1 | -8 | 07W | 187 | 10W | 178 | |
| 8 | AX – 2 | -18 | 02W | 182 | 05W | 176 | |
| 9 | BXO – 3 | -25 | 05E | 175 | 02E | 5 | 187 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.