Hydrogen-Alpha Flare Ribbons

Hydrogen-Alpha Flare Ribbons

. A large solar flare observed in the red light of hydrogen alpha (Ha), showing two extended, parallel flare ribbons in the chromosphere. Each image is 200 million meters in width, subtending an angle of 300 arc seconds or about one sixth of the angular extent of the Sun. These photographs were taken at the Big Bear Solar Observatory on 29 April 1998. (Courtesy of Haimin Wang).

Copyright 2010, Professor Kenneth R. Lang, Tufts University