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A supernova progenitor (SN progenitor) is a star or star system (or anything) that produces a supernova. They can be classified by the overall type of supernova.
The progenitor of a core collapse supernova (i.e., of virtually any type supernova other than Type Ia, a core collapse supernova progenitor) is a massive post-main-sequence star within a range roughly of 25 to 40 or 50 solar masses during its main-sequence; it is thought that above this range, the core collapse will not cause a supernova explosion and even within the range, it is thought some may collapse without the explosion and the question of which circumstances lead to an explosive collapse is still an area of debate and study interest. Some such massive stars have exotic phases within their post main-sequence, such as Wolf-Rayet stars. The variety of observed core collapse supernovae depends both on the star's mass and on any binary-star interaction the star underwent and attempts are made to model the type of such interaction that might lead to an observed unusual supernova.
The progenitor of a Type Ia supernova (Type Ia supernova progenitor) is a white dwarf with a companion, either a star feeding it sufficient mass (mass transfer) to trigger a fusion runaway (generally near the Chandrasekhar mass) or another white dwarf with which it collides: these two theories are known as the single degenerate model and the double degenerate model, and it is considered possible that both occur. In the former case, the notion that it occurs near a particular mass (the Chandrasekhar limit) suggests a straight-forward reason why they may be taken as standard candles, but the latter case makes such a theory less straight forward. The former case of accretion is also somewhat similar to the progenitor of a nova: which is fusion occurring on the surface of a white dwarf due to accretion. The circumstances leading to each is a topic of active research, including the notion that a nova can trigger a Type Ia supernova, possibly even if the White dwarf lacks the full Chandrasekhar mass (a sub-Chandrasekhar mass detonation).