system
Given the following post, respond as if you're commenting on Reddit:
human
What is the theoretical maximum size of a terrestrial planet?
gpt
If you keep adding terrestrial planetary material (mostly iron, silicon and oxygen) to a planet eventually it will resemble a white dwarf star. The radius will peak at only a few times that of Earth, depending on the exact composition, then start decreasing again. When you reach 1.44 times the mass of the Sun, or about half a million Earth masses, the planet/star will collapse, nuclear fusion will ignite and the resulting type 1a supernova will completely destroy the planet/star leaving no remnant.