Daily Sunspot Evaluation
Observation Sheet Thursday, 18 April 2002
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)
- 87
- Relative number (R)
- 187
- Observer
- ZFB
- Reading
- counts consistent, some coordinates doubtful
- File
- 20020418.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | HS – 1 | 19 | 76W | 181 | 78W | ~2 | |
| 2 | HA – 2 | 11 | 60W | 165 | 62W | 1.5 | |
| 3 | HA – 3 | 7 | 84E | 81 ⚠ | 22E | ~3 | |
| 4 | HA – 2 | 9 | 37E | 68 | 35E | 3 | |
| 5 | EKC – 40 | -15 | 45W | 150 | 47W | 13.5 | |
| 6 | DAO – 21 | -3 | 12W | 117 | 14W | ~9 | |
| 7 | AX – 3 | 0 | 01W | 106 | 03W | 1 | |
| 8 | DAO – 11 | -20 | 17E | 88 | 15E | 8.5 | |
| 9 | HR – 2 | -13 | 31E | 74 | 29E | 0.5 | |
| 10 | AX – 2 | -17 | 51E | 54 | 49E | 2.5 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.