A stellar nova is a recurring eruption that occurs in a binary star system, typically involving a white dwarf star that accretes material from a companion star. When the white dwarf accumulates enough mass and material, the surface layers reach conditions conducive to runaway thermonuclear fusion. This fusion process generates immense amounts of energy, causing the star’s outer envelope to rapidly expand and brighten dramatically. Although the energy release is highly luminous, the nova itself represents a surface explosion rather than the complete destruction of the star. The system then sheds the excess energy and material back into space, and the process of material accretion and subsequent explosive burning can repeat over timescales ranging from years to millennia.