system
Given the following post, respond as if you're commenting on Reddit:
human
Are there objects in the universe that are as massive as stars but aren't giant balls of Hydrogen producing light?

Basically, is it possible for a solid matter object to be the size of the Sun and have planets orbiting it without having the normal characteristics of a star? Just a giant ball of rock instead of gasses.
gpt
There's no astrophysically feasible way for an accumulation of rocky matter the size of a star to occur. The atomic matter in the universe is, after all, about 98% hydrogen and helium with only a smattering of the heavier elements like oxygen, silicon, iron, and nickel that make up Earth and other rocky planets. The reason rocky planets form in the inner solar system is that the heat and radiation pressure prevent large gas accumulations from forming very close in to the star, whereas the denser, heavier materials can clump up more easily. But they represent a tiny fraction of the mass of a forming stellar system.