... The Sun's visible surface features large scale magnetic phenomena-- sunspots --rising and falling in an 11-year cycle and sometimes violently erupting. ...
... hot gases on the Sun--fastest near the equator, as the motion of sunspots shows--helps create electric currents in this manner ... The Sun also has a polar magnetic field, and its polarity reverses in each sunspot cycle, every 11 years or so. ...
... Sunspot cycle (or solar cycle)--an irregular cycle, averaging about 11 years in length, during which the number of sunspots (and of their associated outbursts) rises and then drops again. ...
... and observes mountains on the Moon, sunspots (also discovered independently by ... a German amateur astronomer, announces the discovery of the 11-year sunspot cycle ... a violent and rapid eruption near a sunspot; 17 hours later a large magnetic storm ...
... Meanwhile the 11-year sunspot cycle advanced towards its peak, bringing a significant growth in the the soft X-rays and extreme ultraviolet (EUV) emitted by the Sun. ...
... Who Discovered Sunspots? . "Soda-Bottle Magnetometer" . Magnetism and Weather . ... But the Sun's magnetism is different, it has foci right on the surface, in sunspots. ...