system
Given the following post, respond as if you're commenting on Reddit:
human
How small can a star be?

Theoretically could our sun br the size of earth and still function similarly to how it does now?
gpt
In terms of mass, objects below 80 times the mass of Jupiter are not big enough to ignite hydrogen fusion and are classified as brown dwarves. Objects below about 12 times the mass of Jupiter are not hot enough to fuse deuterium.

In terms of radius, neutron stars are extremely dense and can be below 10 km in radius despite being similar to the sun in mass. White dwarves are in between, about as massive as the sun but about as wide as the Earth.