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Sunspots and active regions
The following active regions with sunspot groups were visible on the Sun on July 31, 1999. Coordinates are given as of the end of the day.
| Group ID | Location | Number of sunspots | Area (msh) | Type | CM Passage | Disappearance (W90) | Reappearance (W270) | |
|---|---|---|---|---|---|---|---|---|
| № 8653 | N29 | W55 | 04 | 0020 | BETA | Jul 27, 1999 | Aug 4, 1999 | Aug 18, 1999 |
| № 8651 | N24 | E39 | 26 | 0510 | BETA-GAMMA | Aug 4, 1999 | Aug 11, 1999 | Aug 25, 1999 |
| № 8650 | N16 | E39 | 01 | 0050 | ALPHA | Aug 4, 1999 | Aug 11, 1999 | Aug 24, 1999 |
| № 8649 | S15 | W27 | 25 | 0170 | BETA | Jul 30, 1999 | Aug 6, 1999 | Aug 19, 1999 |
| № 8648 | N23 | E19 | 04 | 0010 | BETA | Aug 2, 1999 | Aug 9, 1999 | Aug 23, 1999 |
| № 8647 | S17 | E00 | 11 | 0040 | BETA | Aug 1, 1999 | Aug 8, 1999 | Aug 21, 1999 |
| № 8645 | S25 | W00 | 37 | 0620 | BETA-GAMMA | Aug 1, 1999 | Aug 8, 1999 | Aug 22, 1999 |
| № 8644 | S25 | W20 | 02 | 0020 | BETA | Jul 30, 1999 | Aug 6, 1999 | Aug 20, 1999 |
| № 8640 | N16 | W52 | 04 | 0100 | BETA | Jul 28, 1999 | Aug 4, 1999 | Aug 17, 1999 |
| № 8636 | N21 | W87 | 04 | 0080 | BETA | Jul 25, 1999 | Aug 1, 1999 | Aug 15, 1999 |
Solar cycle progression
The average monthly sunspot number (SSN) from January 1970 to July 1999. The gray background is the average SSN index.
