Final answer:
The life cycle of a star with one stellar mass involves stages such as contracting protostar, stable main-sequence star, and moving off the main sequence towards the red-giant region.
Step-by-step explanation:
The life cycle of a star with one stellar mass begins as a contracting protostar. It then becomes a stable main-sequence star and eventually moves off the main sequence toward the red-giant region. As the star continues to evolve, it will eventually form a carbon-oxygen core, marking the end of nuclear energy generation at the center of the star.
Thus, the star's death is near at this point, but the specific outcome depends on its mass, composition, and the presence of any nearby companion stars. Stars with masses less than about 1.4 times the total mass of the Sun will likely end up as white dwarfs, while more massive stars may have explosive finishes, such as supernovae or black hole formation.