Mass formation of a neutron star Vs White dwarf

Question

I have been researching the different outcomes of a star's death. I understand that the main factor is the star's mass at the end of its life, along with others such as its metallicity. Well, the thing is that typically one tends to say:

• If $M\sim M_S$, the star will become a white dwarf sustained by the degenerate electron pressure.
• If $M>8M_S$, the result is a neutron star after a core-collapse supernova.

Ok, but what happens between the sun mass and the eight sun masses? I assume that there is some uncertainty about the exact value but what it the limit between one situation or another?

Answer 1

Although the mass of a white dwarf is limited by the Chandrasekhar limit to a maximum of about $1.4$ solar masses, the star from which the white dwarf evolved may have originally been more massive than this.

Stars with masses between $0.5$ and $8$ solar masses cannot fuse carbon into heavier elements, and so do not experience the run-away core collapse that results in a supernova. Instead, they progress through the red giant phase and enter the asymptotic giant branch of the Hertzsprung-Russell diagram, where they gradually expel most of their mass in concentric shells known as a planetary nebula. The stellar remnant that is left at the centre of the planetary nebula is a white dwarf.

Stars with masses less than $0.5$ solar masses are not even massive enough to fuse helium. Once they have exhausted their hydrogen fuel, they progress directly to the white dwarf stage without becoming a red giant first.

This diagram at Wikipedia neatly summarises the various sequences of stellar evolution.