Hubble finds sizzling details about young star FU Orionis

In 1936, astronomers saw a puzzling event in the constellation Orion: the young star FU Orionis (FU Ori) became a hundred times brighter in a matter of months. At its peak, FU Ori was intrinsically 100 times brighter than our sun. Unlike an exploding star, though, it has declined in luminosity only languidly since then.