Light Bridges on the Sun
Explanation: Bridges the length of a planet can form on the Sun
in a matter of hours. Known as light
bridges, these structures may form as large sunspot groups decay. Above, one of the sharpest
photographs of the Sun ever taken
shows two such light
bridges that appeared late last month. The 5000-kilometer long bridges
connect moderately dark penumbral
regions across the cool abyss of two dark sunspot umbras. A movie shows that material
tends more to rise from below and fall rather than to cross the light bridges.
Bright bubbling granules surround
the sunspot
group. The impressive details on this recently released
picture from the Swedish Solar Vacuum
Telescope were made possible by new adaptive
optics that correct for the blurring of the Earth's
atmosphere. What eventually became of the light
bridges? As days progressed, the bridge region expanded to fill the void as
the sunspots moved apart and decayed.
