Yours, Etc.: Origins and Uses of 8 Sign-Offs
|solar flare |
A sudden eruption of hydrogen gas in the chromosphere of the Sun, usually associated with sunspots. Solar flares may last between several hours and several days, and have temperatures ranging from 20 to 100 million degrees K. The energy of a solar flare, which consists primarily of charged particles and x-rays, is comparable to tens of millions of hydrogen bombs, but is less than one-tenth the total energy emitted by the Sun every second. First observed in 1859, solar flares dramatically affect the Sun's weather and the solar wind, and are correlated with the appearance of auroras on the Earth. See also prominence.