"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.

Astronomers have captured a jaw-dropping picture of star that exploded twice. It is the first time researchers have obtained visual evidence that a star met its end in a so-called “double detonation.” By studying the centuries-old remains of supernova SNR 0509-67.