Daily Sunspot Evaluation
Observation Sheet Sunday, 31 March 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)
- 55
- Relative number (R)
- 145
- Observer
- TA
- Reading
- all checks consistent
- File
- 19910331.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | ? – 2 | 18 | 77W | 171 | 78W | 7 | 134 |
| 2 | AX – 2 | 20 | 03E | 91 | 02E | 2.5 | 137 |
| 3 | EKC – 26 | 15 | 37E | 57 | 36E | 11 | 138 |
| 4 | CKI – 5 | 10 | 66E | 28 | 65E | 10 | 139 |
| 5 | ? – 3 | -23 | 83W | 177 | 84 | 4 | 127 |
| 6 | ? – 3 | -8 | 80W | 174 | 81W | 3 | 140 |
| 7 | AX – 1 | -12 | 70W | 164 | 71W | 0.5 | 135 |
| 8 | BRO – 2 | -15 | 49W | 143 | 50W | 8 | 129 |
| 9 | DKC – 11 | -10 | 40E | 54 | 39E | 10 | 141 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.