Active areas
Sunspots and active regions
By the end of the day, the following active regions with sunspots could be observed on the Sun's surface
| Group ID | Location | Number of sunspots | Area (msh) | Type | CM Passage | Disappearance (W90) | Reappearance (W270) | |
|---|---|---|---|---|---|---|---|---|
| № 8801 | S23 | W01 | 02 | 0000 | BETA | Dec 16, 1999 | Dec 23, 1999 | Jan 6, 2000 |
| № 8800 | N11 | E60 | 01 | 0020 | ALPHA | Dec 21, 1999 | Dec 27, 1999 | Jan 10, 2000 |
| № 8799 | S09 | E60 | 02 | 0080 | BETA | Dec 21, 1999 | Dec 27, 1999 | Jan 10, 2000 |
| № 8798 | S13 | E60 | 05 | 0100 | BETA | Dec 21, 1999 | Dec 27, 1999 | Jan 10, 2000 |
| № 8797 | S34 | W02 | 07 | 0080 | BETA | Dec 16, 1999 | Dec 23, 1999 | Jan 6, 2000 |
| № 8796 | S27 | W18 | 01 | 0000 | ALPHA | Dec 15, 1999 | Dec 22, 1999 | Jan 5, 2000 |
| № 8795 | S14 | W47 | 03 | 0030 | BETA | Dec 12, 1999 | Dec 19, 1999 | Jan 2, 2000 |
| № 8794 | S13 | W08 | 01 | 0010 | ALPHA | Dec 15, 1999 | Dec 22, 1999 | Jan 5, 2000 |
| № 8792 | N16 | W11 | 01 | 0000 | ALPHA | Dec 15, 1999 | Dec 22, 1999 | Jan 5, 2000 |
| № 8790 | N15 | W69 | 01 | 0000 | ALPHA | Dec 11, 1999 | Dec 18, 1999 | Dec 31, 1999 |
| № 8788 | N11 | W75 | 05 | 0170 | BETA | Dec 10, 1999 | Dec 17, 1999 | Dec 31, 1999 |
Solar cycle progression
Average monthly sunspot number (SSN) from 1970, January to 1999, December. Gray background - average solar cycle.

