Sunspots and active regions
The following active regions with sunspot groups were visible on the Sun on April 18, 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) | |
|---|---|---|---|---|---|---|---|---|
| № 595 | S09 | E55 | 03 | 0010 | Beta | Apr 23, 2004 | Apr 30, 2004 | May 14, 2004 |
| № 594 | N15 | E27 | 04 | 0050 | Alpha | Apr 21, 2004 | Apr 28, 2004 | May 12, 2004 |
| № 592 | S11 | E06 | 01 | 0010 | Alpha | Apr 19, 2004 | Apr 26, 2004 | May 10, 2004 |
| № 591 | S16 | W65 | 07 | 0060 | Beta | Apr 14, 2004 | Apr 21, 2004 | May 5, 2004 |
Solar cycle progression
The average monthly sunspot number (SSN) from January 1975 to April 2004. The gray background is the average SSN index.
