
1) Unit of time
Found on
https://www.crosswordclues.com/clue/solar-cycle

The solar cycle (or solar magnetic activity cycle) is the periodic change in the Sun`s activity (including changes in the levels of solar radiation and ejection of solar material) and appearance (visible in changes in the number of sunspots, flares, and other visible manifestations). Solar cycles have an average duration of about 11 years. They h....
Found on
http://en.wikipedia.org/wiki/Solar_cycle
[calendar] The solar cycle is a 28-year cycle of the Julian calendar with respect to the week. It occurs because leap years occur every 4 years and there are 7 possible days to start a leap year, making a 28 year sequence. This cycle also occurs in the Gregorian calendar, but it is interrupted by years such as 1700, 1800, 1900 and 2100, whi...
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http://en.wikipedia.org/wiki/Solar_cycle_(calendar)

period in which several important kinds of solar activity repeat themselves. The cycle, lasting about 22 years on average, includes two 11-year ...
Found on
http://www.britannica.com/eb/a-z/s/121

a period of approximately 11 years characterizing the slowly variable components of solar activity
Found on
http://www.electropedia.org/iev/iev.nsf/display?openform&ievref=705-07-84

The 11-year variation in sunspot activity.
Found on
http://www.encyclo.co.uk/visitor-contributions.php

The approximately 11-year quasi-periodic variation in frequency or number of solar active events.
Found on
http://www.encyclo.co.uk/visitor-contributions.php

The approximately 11-year quasi-periodic variation in frequency or number of solar active events.
Found on
http://www.seasky.org/astronomy/astronomy-glossary.html

The approximately 11-year, quasi-periodic variation in the frequency or number of solar active events.
Found on
http://www.solarviews.com/eng/terms.htm

solar cycle The main periodic cycle in the sun's activity that occurs over about an eleven-year period. The period is not constant, varying between about 9.5 and 12.5 years. During the cycle, changes occur in the sun's internal magnetic field and in its surface disturbance level.
Found on
http://www.wordinfo.info/words/index/info/view_unit/1978/2

The periodic change in sunspot numbers. It is the interval between successive minima and is about 11.1 years.
Found on
https://www.encyclo.co.uk/local/20128

The approximately 11 year quasi-periodic variation in frequency or number of solar active events. See also: Sun.
Found on
https://www.encyclo.co.uk/local/20687
No exact match found.