Sunspots and active regions
The following active regions with sunspot groups were visible on the Sun on September 17, 2004. 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) | |
|---|---|---|---|---|---|---|---|---|
| № 673 | S12 | E63 | 15 | 0240 | Beta-Gamma | Sep 23, 2004 | Sep 29, 2004 | Oct 13, 2004 |
| № 672 | N05 | W15 | 45 | 0230 | Beta-Delta | Sep 17, 2004 | Sep 23, 2004 | Oct 7, 2004 |
Solar cycle progression
The average monthly sunspot number (SSN) from January 1975 to September 2004. The gray background is the average SSN index.
