Terminatsioonifaas

Terminatsioonifaas, also known as the termination phase, is a critical stage in the life cycle of a star, particularly for stars with masses similar to or greater than that of the Sun. This phase begins when a star exhausts the nuclear fuel in its core, leading to a significant decrease in its luminosity and temperature. The star then transitions from the main sequence to the red giant branch, where it expands and cools.

During the terminatsioonifaas, the star's outer layers are expelled into space, forming a planetary nebula. This process is driven by the star's intense radiation and strong stellar winds. The core of the star, now composed primarily of carbon and oxygen, becomes a white dwarf. The white dwarf is extremely dense, with a mass comparable to that of the Sun but a radius similar to that of Earth.

The duration of the terminatsioonifaas varies depending on the mass of the star. For a star like the Sun, this phase is relatively short, lasting only a few thousand years. However, for more massive stars, the terminatsioonifaas can be much longer, potentially lasting tens of thousands of years.

The terminatsioonifaas marks the end of a star's life as a main sequence star and the beginning of its final stages as a white dwarf. This phase is a crucial step in the evolution of stars and the enrichment of the interstellar medium with heavy elements.