This ultraviolet image of the Sun shows one of the largest solar flares ever seen. The flare, which erupted in November 2003, is the bright region along the Sun's right limb. The horizontal "spikes" extending to the right and left of the flare are not real; they are an artifact produced by the imaging instrument, which was overloaded by the intense brightness of this flare.
Click on image for full size
Image courtesy SOHO (NASA & ESA).

Solar Flares

Solar flares are essentially huge explosions on the Sun. Flares occur when intense magnetic fields on the Sun become too tangled. Like a rubber band that snaps when it is twisted too far, the tangled magnetic fields release energy when they "snap". Solar flares emit huge bursts of electromagnetic radiation, including X-rays, ultraviolet radiation, visible light, and radio waves. The energy emitted by a solar flare is more than a million times greater than the energy from a volcanic explosion on Earth!

Although solar flares can be visible in white light, they are often more readily noticed via their bright X-ray and ultraviolet emissions. Coronal mass ejections often accompany solar flares, though scientists are still trying to determine exactly how the two phenomena are related. Solar flares burst forth from the intense magnetic fields in the vicinity of active regions on the Sun. Solar flares are most common during times of peak solar activity, the "solar max" years of the sunspot cycle.

Last modified April 29, 2016 by Jennifer Bergman.

You might also be interested in:

Traveling Nitrogen Classroom Activity Kit

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

The Sun's Magnetic Field

The Sun has a very large and very complex magnetic field. The magnetic field at an average place on the Sun is around 1 Gauss, about twice as strong as the average field on the surface of Earth (around...more

Electromagnetic Radiation

Electromagnetic radiation is the result of oscillating electric and magnetic fields. The wave of energy generated by such vibrations moves through space at the speed of light. And well it should... for...more

Radio Waves

Radio waves are a type of electromagnetic radiation. A radio wave has a much longer wavelength than does visible light. We use radio waves extensively for communications. Radio waves have wavelengths as...more

Active Regions on the Sun

An active region on the Sun is an area with an especially strong magnetic field. Sunspots frequently form in active regions. Active regions appear bright in X-ray and ultraviolet images. Solar activity,...more

Sunspots

Sunspots are dark, planet-sized regions that appear on the "surface" of the Sun. Sunspots are "dark" because they are cooler than their surroundings. A large sunspot might have a central temperature of...more

Projects - for Science Fairs & Beyond

Interested in doing a project related to space weather for a science fair? The Stanford SOLAR Center provides information about space weather monitors that you can build yourself, including the Sudden...more

Sunspots and Magnetic Fields

Sunspots are caused by extremely strong, localized magnetic fields on the Sun. "Jet streams" of plasma that form deep within the Sun's convective zone produce powerful magnetic fields. When these loops...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA