Sunspots and active regions
The following active regions with sunspot groups were visible on the Sun on April 20, 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 | S21 | E30 | 04 | 0020 | Beta | Apr 23, 2001 | Apr 30, 2001 | May 14, 2001 |
| № 9434 | N19 | W21 | 04 | 0050 | Beta | Apr 19, 2001 | Apr 26, 2001 | May 10, 2001 |
| № 9433 | N17 | E66 | 17 | 0590 | Beta | Apr 26, 2001 | May 3, 2001 | May 16, 2001 |
| № 9432 | N07 | E08 | 09 | 0050 | Beta | Apr 21, 2001 | Apr 28, 2001 | May 12, 2001 |
| № 9429 | N08 | W02 | 01 | 0060 | 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.
