Sunspot Activity 1000 C.E. to Present
| Years (c.e.) |
Name |
| 1010 to 1050 |
Oort Minimum |
| 1100 to 1250 |
Medieval Maximum |
| 1280 to 1340 |
Wolf Minimum |
| 1420 to 1530 |
Spörer Minimum |
| 1645 to 1715 |
Maunder Minimum |
| 1790 to 1820 |
Dalton Minimum |
| 1950 to Present |
Modern Maximum |
Swiss astronomer Johann Rudolf Wolf (1816–1893) devised a system for counting sunspots in 1848. The Wolf Number is named in his honor. Astronomers count sunspots from various observation points across the globe, then average those counts to come up with the official Wolf Number for that period.
