Wednesday, 21 April, 2021 - 04:45 Multiple images of a single distant supernova within a cluster of galaxies called MACS J1149.6+2223, located more than 5 billion light-years away, are seen in an image from NASA taken by the Hubble Space Telescope and released March 5. REUTERS Cairo - Asharq Al-Awsat When a white dwarf star explodes as a supernova, it may detonate like a nuclear weapon on Earth, a new study published in the latest issue of the journal Physical Review Letters revealed. White dwarfs are the dim, fading, Earth-size cores of dead stars that are left behind after average-size stars have exhausted their fuel and shed their outer layers. Our sun will one day become a white dwarf, as will more than 90% of the stars in our galaxy.