active Sun

active Sun

The term applied to the Sun around the maximum of the sunspot cycle, when the profusion of active regions ensures a high level of solar activity. Compare quiet Sun.

active Sun

[′ak·tiv ′sən]
(astronomy)
The Sun during the portion of its 11-year cycle in which sunspots, flares, prominences, and variations in radio-frequency emission reach their maximum.
References in periodicals archive ?
James Madden, forecaster with Exacta Weather, said a combination of low solar activity and a less magnetically active sun will mean much colder-than-average weather conditions for Ireland.
But anything living on the world may have to withstand extra large doses of radiation from its active sun.
Fifth Hinode science meeting; exploring the active sun.
At the end of April and into May and June, the night sky becomes brighter, especially at higher latitudes and, despite a reasonably active Sun, auroral reports become fewer.
An active Sun can disrupt satellite, communication, and power systems on earth.
Meanwhile, German prestige cosmetics and toiletries brand Marbert has launched two products in its Active Sun range, which the company claims reflect the new EU sun protection regulations.
The proposed method for the tracking is based on heliostat operation, or active sun tracking (Red Rock, 2008).
It includes Avon Bronze Active sun Llotion F20, Active sun block stick SPF25 and a cooling aloe ice gel and after sun shower gel for hair and body to refresh and invigorate.
But Solomon says they have "strong evidence' against two proposed theories that don't lean primarily on chemistry: a dynamic model involving the upward movement of ozone-poor air from the troposphere into the stratosphere, and the "old-nitrogen' theory, which holds that the highly active sun during the last solar cycle generated large levels of ozone-destroying nitric oxide (SN: 10/11/86, p.
She estimates there are 1,000 active Sun City volunteers who contribute their time and efforts to various organizations in the Georgetown area, and an additional 150-200 residents who serve on nonprofit boards locally.