Daily Sunspot Evaluation
Observation Sheet Thursday, 15 February 1951
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)
- 6
- Number of spots (f)
- 23
- Relative number (R)
- 83
- Observer
- ET
- Reading
- all checks consistent
- File
- 19510215.jpg
Sunspot groups
| No | Group (class – spots) | r | p | Margin no. |
|---|---|---|---|---|
| 1 | D – 7 | 0.57 | 41 | |
| 2 | A – 2 | 0.88 | 57 | |
| 3 | B – 4 | 0.61 | 67 | |
| 4 | C – 2 | 0.18 | 121 | |
| 5 | B – 4 | 0.86 | 265 | |
| 6 | C – 4 | 0.42 | 279 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.