Daily Sunspot Evaluation
Observation Sheet Sunday, 28 July 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)
- 12
- Number of spots (f)
- 104
- Relative number (R)
- 224
- Observer
- TA
- Reading
- all checks consistent
- File
- 19910728.jpg
Sunspot groups
| No | Group (class – spots) | B | Δ L | L | Δ Lf | U | Margin no. |
|---|---|---|---|---|---|---|---|
| 1 | HA – 3 | 2 | 16W | 339 | 19W | 04 | 394 |
| 2 | DKC – 39 | 10 | 14W | 337 | 17W | 6.5 | 393 |
| 3 | BRI – 7 | 8 | 01E | 322 | 02W | 4 | 410 |
| 4 | AX – 4 | 12 | 45E | 278 | 42E | 2 | 408 |
| 5 | AX – 3 | -19 | 63W | 26 | 66W | 2 | 411 |
| 6 | BRO – 7 | -18 | 59W | 22 | 62W | 8.5 | 389 |
| 7 | BXO – 3 | -21 | 36W | 359 | 39W | 6 | 402 |
| 8 | DAO – 7 | -15 | 35W | 358 | 38W | 10 | 391 |
| 9 | BXI – 8 | -6 | 26W | 349 | 29W | 4 | 412 |
| 10 | HK – 6 | -18 | 48E | 275 | 45E | 6 | 407 |
| 11 | HS – 2 | 7 | 39W | 2 | 42W | 2 | 369 |
| 12 | HK – 15 | 9 | 31W | 354 | 34W | 6 | 388 |
Class as written on the sheet (? = group the observer marked as uncertain). ⚠: the coordinates of this row do not agree with each other.