What is the approximate initial mass threshold for a star to undergo a core collapse supernova?

Greater than 8 M extregistered extsuperscript{ extcircled}O.

The fundamental requirement for a star to end its life in a dramatic core-collapse supernova is its initial mass. Stars possessing significantly larger masses than our Sun, specifically those generally considered to be eight times the Sun's mass ($8 M_{ extregistered extsuperscript{ extcircled}O}$) or exceeding this value, generate the immense internal gravitational pressure necessary to continue nuclear fusion deep into heavier elements. This high mass ensures that the star's internal engine can sustain reactions until the core turns into iron. If the star's mass falls below this critical threshold, the star will exhaust its fuel, inflate into a red giant, expel its outer layers as a planetary nebula, and peacefully contract into a white dwarf rather than collapsing catastrophically.