Final answer:
The Sun will evolve into a Red Giant star, expand significantly, and turn more luminous and cooler, eventually shedding its layers to become a white dwarf.
Step-by-step explanation:
Our Sun will eventually become a Red Giant star. This is the next stage in a star's life as it transitions from the main-sequence band to their later stages of existence. Stars like our Sun, which are not massive enough to become red supergiants, undergo a transformation where their cores contract while their outer layers expand significantly. As the Sun evolves, it will become more luminous and cooler, eventually becoming so large that its size could envelop the orbit of Mars.
During this phase, our Sun’s atmosphere would not be deep red but more of an orange or orange-red color. After the red giant stage, our Sun is expected to shed its outer layers and expose its hot inner core as a white dwarf, cooling slowly over billions of years.