Astronomers have captured the first-ever visual evidence of awhite dwarf star exploding twice in a remarkable supernova event. The discovery, made by studying the remnants of supernova SNR 0509-67.5 with the European Southern Observatory’s Very Large Telescope (ESO’s VLT),

"This tangible evidence of a double detonation not only contributes towards solving a long-standing mystery, but also offers a visual spectacle."

The shattered star at the center was once a white dwarf, a stellar ember no larger than Earth, yet almost as heavy as the Sun. Standard textbooks say such dwarfs need to fatten up to 1.4 solar masses — the Chandrasekhar limit — before runaway fusion turns them into Type Ia supernovae.