Sun is the core and the main body of the Solar System.
Sun is a star, he acts cool but realistically he is nervous a lot for not only his safety, but the safety of his planet, especially Earth, he is also scared for a lot of things like bigger stars, Black Holes, White Dwarfs, and scary and creepy stars.
Red Giant Phase
In 5 billion years from now, the Sun will stop bullring hydrogen and start burning helium. This will cause the Sun to cool down, becoming red, loose mass, and greatly expand, so big he will consume Mercury, Venus, and possibly Earth, but more likely not. which will fry the Earth making life impossible.
White Dwarf Phase
About a billion years after the Red Giant Phase the Sun will release his outer layers, which will create a planetary nebula causing the Sun to shrink to the size of the Earth. At this time Andromed and Milky has Way would be colliding. The future of the solar system is where the Sun will either get eaten by the new core, or will be ejected out of the galaxy if ejected, the solar system will still be alive but eventually, all the planets orbiting Sun still will stop orbiting the Sun and will fall down into the Sun, leaving only the Sun left. Over the next trillion years, it will fade away, becoming a black dwarf.
Sun used to have a wife with him, her name was Nemesis, and surprisingly Sun didn't think that she would be bad, despite her name, he was probably just too caught up in her beauty. Anyways Sun would describe her as a girl who doesn't care about much, an most of the time think on her own, but he knows she has a "heart" of gold. They were a lovely couple until one day, about 30 million years ago, Earth came home from her visit with her cousin, and as Earth was explaining how well her visit was while Nemesis was throwing asteroids around, one of which, crashed into Earth, and this killed her current life(the dinosaurs) Sun then noticed Nemesis throwing the asteroids and asked her if she threw the asteroid, Nemesis said yeah, Sun explained she can't do that, and Nemesis replied she can do whatever she wants and complained to Sun why he cared for his planets saying "They are nothing but puny balls of rocks or gas" and she even said she never cared for the planets, this caused Sun to decide to break up with her saying, "Well, then if you don’t want our planets, I don’t want you!", Nemesis took it as a joke saying that he can't be serious because he could literally not exist without her, then Sun told her to "Get out.", Nemesis then asked what he meant then Sun ejected her while yelling "GET OUT!", then Nemesis said that he swears she will come back for revenge before flying away into space, gone to never return, and Sun never saw her since.