Solar Activity

The output of the Sun in all forms, light, solar wind, and energetic particles, is not constant. It varies with both time (seconds to centuries!) and position on the Sun. These changes are called solar activity and are probably reflections of changes below the Sun's surface. Scientists can study the output and how it varies to probe the workings of the Sun.

The Sun's energy output takes two main forms: electromagnetic radiation and the emission of charged particles. The charged particles that carry a portion of the Sun's energy include both the relatively low-energy plasma of the solar wind and high-energy particles which have been accelerated to velocities near the speed of light. Solar activity produces space weather that affects Earth.

Types of solar activity include:

Sunspots
Solar Flares
Coronal Mass Ejections
Coronal Holes
Solar Plumes
The Solar Cycle

SOHO Pick of the Week -- SOHO

Back to Sun

January 7, 2009: Danger ahead as the Sun goes quiet -- New Scientist
November 2, 2008: Spicules: Jets on the Sun -- APOD
October 4, 2008: A solar prominence unfurls -- APOD
September 24, 2008: Active Region 1002 on an unusually quiet Sun -- APOD
June 5, 2008: Sun's corona puts a twist on its pitches -- Sky & Telescope
June 3, 2008: Giant "tornadoes" seen erupting from the sun -- National Geographic
June 1, 2008: A twisted solar eruptive prominence -- APOD
February 6, 2008: A sunspot in the new solar cycle -- APOD
January 2, 2008: Third instrument for NASA's Solar Dynamics Observatory arrviese at Goddard -- NASA GSFC
November 28, 2007: UNH scientists report first findings on key astrophysics problem -- Eurekalert
May 30, 2007: News from your favorite star -- Astronomy.com
April 27, 2007: NOAA announces next solar storm cycle will likely start next March -- EurekAlert!
April 25, 2007: The quest to predict the next space "hurricane" season -- NASA GSFC
March 22, 2007: Hinode studies the Sun -- Astronomy.com
March 21, 2007: Solar activity won't break drought -- Australian Broadcasting Company
February 19, 2007: Surprises from the Sun's south pole -- European Space Agency
February 6, 2007: Sun storm: a coronal mass ejection -- NASA GSFC APOD
January 25, 2007: Twin spacecraft swing past Moon to prepare for 3-D solar studies -- SpaceDaily
January 4, 2007: 1000th orbit for the Cluster mission -- SpaceDaily

Solar activity news from 2006 and earlier