What signals the beginning of the events that lead to the end of a a star's life?

What signals the beginning of the events that lead to the end of a a star's life?



The end of Hydrogen fusion in the core.

The end of Helium fusion in the core.

A collapse of the core.

The core explodes.What signals the beginning of the events that lead to the end of a a star's life?When the elements in the star get fused, they go from H to He to denser and denser elements, but when it reaches the the point where it's about to create Iron, that's the brink. The final stage is reached when the star begins producing iron. Since Iron nuclei are more tightly bound than any heavier nuclei, if they are fused they do not release energy鈥攖he process would, on the contrary, consume energy. This really messes up the star and causes the star to 'die'.What signals the beginning of the events that lead to the end of a a star's life?The end of helium fusion in the core. When all hydrogen has been fused to helium, helium will then fuse into larger elements. At this point, the star begins to expand into a red giant. The expansion will continue until iron begins to form in the star's core, then the star will begin to collapse. After that, the star will either collapse into a white dwarf or explodes in a supernova leaving a black hole or a neutron star. The core does not explode or collapse.What signals the beginning of the events that lead to the end of a a star's life?It depends on what kind of star. For our sun, is the end of fussing Hydrogen.

For really massive stars, its when they start to fuse elements into iron.



But since Hydrogen is the primary fuel to all stars, I would have to say that The end of Hydrogen fusion in the core is the signal of star ending its life.What signals the beginning of the events that lead to the end of a a star's life?
Itz the end of nuclear fuel{hydrogen}w矛ch results in domination of gravitational force%26amp;initiates the destructive sequence