This animation shows how the explosion of Tycho's Supernova in 1572 most likely took place. In Type Ia supernova binary systems, the more massive star of the pair will age faster and eventually becomes a white dwarf star. When the slower-evolving companion star subsequently ages to the point where it begins to balloon in size, it spills hydrogen onto the dwarf. The hydrogen accumulates, gradually fusing into heavier elements until it reaches a critical and precise mass threshold, called the Chandrasekhar limit, where it explodes as a titanic nuclear fusion bomb. The companion star goes hurtling off into space, retaining the velocity of its orbital motion when the explosion disrupted the system.
Credit: NASA, ESA and P. Ruiz-Lapuente (University of Barcelona)