Solar cycle 2 was the second
solar cycle
The Solar cycle, also known as the solar magnetic activity cycle, sunspot cycle, or Schwabe cycle, is a periodic 11-year change in the Sun's activity measured in terms of Modern Maximum, variations in the number of observed sunspots on the Sun ...
since 1755, when extensive recording of
sunspot
Sunspots are temporary spots on the Sun's surface that are darker than the surrounding area. They are one of the most recognizable Solar phenomena and despite the fact that they are mostly visible in the solar photosphere they usually aff ...
activity began.
The solar cycle lasted 9 years, beginning in June 1766 and ending in June 1775. The maximum
smoothed sunspot number
The Wolf number (also known as the relative sunspot number or Zürich number) is a quantity that measures the number of sunspots and groups of sunspots present on the surface of the Sun. Historically, it was only possible to detect sunspots on t ...
observed during the solar cycle was 193.0 (September 1769), and the starting minimum was 18.6.
Sunspot observations by
Alexander Wilson during this period established the
Wilson effect.
See also
*
List of solar cycles
Solar cycles are nearly periodic 11-year changes in the Sun's activity that are based on the number of sunspots present on the Sun's surface. The first solar cycle conventionally is said to have started in 1755. The source data are the revised In ...
References
{{DEFAULTSORT:Solar Cycle 02
Solar cycles