Scientists | Pakistan

WASHINGTON: A supernova — the explosive death of a star — is always violent, blasting material into space while typically leaving behind a compact stellar remnant like a neutron star or black hole. But some supernovas involving the largest stars in the cosmos may be so immensely powerful they leave absolutely nothing behind. Scientists since the 1960s have theorised the existence of these ultra-powerful supernovas, and have now come up with evidence for them — albeit indirect — in research involving black holes and ripples in spacetime called gravitational waves. Such supernovas are predicted to occur in the most enormous stars — those with a mass around 140 to 260 times greater than the sun, according to Hui Tong, a doctoral student in astrophysics at Monash University in Australia and lead author of the study published on Wednesday in the journal Nature. “Despite their enormous mass, they live relatively short lives, about a few million years. For comparison, the sun will live for about 10 billion years, so...