Sunspots and active regions
The following active regions with sunspot groups were visible on the Sun on April 21, 2001. 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) | |
|---|---|---|---|---|---|---|---|---|
| № 9435 | S20 | E16 | 07 | 0030 | Beta | Apr 23, 2001 | Apr 30, 2001 | May 14, 2001 |
| № 9434 | N19 | W36 | 03 | 0030 | Beta | Apr 19, 2001 | Apr 26, 2001 | May 10, 2001 |
| № 9433 | N17 | E54 | 17 | 0700 | Beta-Gamma | Apr 26, 2001 | May 3, 2001 | May 17, 2001 |
| № 9432 | N08 | W04 | 11 | 0050 | Beta | Apr 22, 2001 | Apr 28, 2001 | May 12, 2001 |
| № 9431 | S12 | E17 | 04 | 0030 | Beta | Apr 23, 2001 | Apr 30, 2001 | May 14, 2001 |
| № 9429 | N09 | W16 | 01 | 0050 | Alpha | Apr 21, 2001 | Apr 27, 2001 | May 11, 2001 |
Solar cycle progression
The average monthly sunspot number (SSN) from January 1972 to April 2001. The gray background is the average SSN index.
