Dead Stars Are Breaking Their Size Limit
Dead Stars Are Breaking Their Size Limit For decades, astronomers thought dead stars came with a strict weight limit. A white dwarf — the dense, burnt-out core left behind when a star like the Sun dies — was never supposed to exceed about 1.4 times the mass of the Sun. Pass that threshold, known as the Chandrasekhar limit, and the star should blow itself apart. New computer simulations suggest that rule has a loophole: magnetism. In research published in The Astrophysical Journal Letters, scientists at the Indian Institute of Science and their collaborators followed stars through their entire evolution, tracking what happens as a white dwarf keeps pulling in extra material from a companion. As the white dwarf gains mass, it compresses — and that compression strengthens the magnetic field buried inside it. The field acts like an internal scaffold, holding up far more weight than the classic limit allows. In one simulation, the white dwarf kept growing until it reached roughly 2.4 ti...