What is the life cycle of a high-mass star?

The life cycle of a high-mass star is characterized by several distinct stages, primarily including the main sequence, red supergiant phase, and ultimately a supernova event, which may result in the formation of either a neutron star or a black hole.

During the main sequence stage, a high-mass star fuses hydrogen into helium in its core, which is the primary energy source for the star. This stage can last for millions to tens of millions of years, depending on the mass of the star. Once the hydrogen is depleted, the core contracts and heats up, leading the star to expand into a red supergiant.

In the red supergiant phase, the star undergoes further fusion of heavier elements, creating a layered structure akin to an onion, where heavier elements are fused in the core and lighter elements are found in outer layers. This stage sees significant changes in the star’s size and brightness.

Eventually, when nuclear fusion can no longer sustain the star against gravitational collapse, the core collapses, leading to a supernova explosion. This catastrophic event is responsible for dispersing the outer layers of the star into space, enriching the interstellar medium with heavy elements created during its life cycle.

After the supernova, what remains can