Daily Sunspot Evaluation
Observation Sheet Sunday, 28 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)
- 10
- Number of spots (f)
- 46
- Relative number (R)
- 146
- Observer
- TA
- Reading
- all checks consistent
- File
- 19910428.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | HA – 1 | 8 | 45E | 42 | 42E | 1.5 | 193 |
| 2 | BRI – 13 | 7 | 55E | 32 | 52E | 8 | 194 |
| 3 | EAC – 12 | -30 | 55W | 142 | 58W | 12 | 191 |
| 4 | BRI – 11 | -28 | 01E | 86 | 02W | 6 | 200 |
| 5 | BRO – 2 | -41 | 17E | 70 | 14E | 4.5 | 197 |
| 6 | AX – 1 | -22 | 23E | 64 | 20E | - | 195 |
| 7 | AX – 3 | -17 | 38E | 49 | 35E | 2 | 201 |
| 8 | AX – 1 | -15 | 55E | 32 | 52E | 0.5 | 198 |
| 9 | HA – 1 | -22 | 61E | 26 | 58E | 2 | 199 |
| 10 | HA – 1 | -6 | 72E | 15 | 69E | 2 | 202 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.