Final answer:
The Sun will become a Red Giant in about 5 billion years, eventually shedding its outer layers and ending its life cycle as a White Dwarf. This process involves expansion, shedding mass, and contracting into the dense remnant after the star has exhausted its nuclear fuel.
Step-by-step explanation:
In about 5 billion years, the Sun is expected to become a Red Giant. As a Red Giant, the Sun's outer atmosphere could extend to the orbit of Mars or even beyond. This transformation will mark the twilight years of the Sun's life cycle, as it transitions from the main sequence phase. Stars with masses similar to the Sun typically end their lives not as Black Holes, but as White Dwarfs. Once the Sun has expanded into a Red Giant and shed its outer layers, it will eventually contract into a White Dwarf. The mass of a star determines its ultimate fate: stars with core masses greater than 3 solar masses might end in the formation of a Black Hole, while those with less mass, like our Sun, will avoid such a dense end.
A White Dwarf is the final evolutionary stage for stars like the Sun, after it has lost a significant portion of its mass and the nuclear fuel has been exhausted. During the Red Giant stage, a star like the Sun will experience substantial mass loss, shedding its outer layers and producing a planetary nebula, leaving behind the core which cools and fades over time as a White Dwarf.