What is the difference between a planet and a sub-brown dwarf?

The distinction between planets and sub-brown dwarfs can be difficult to define. A planet is typically defined as a celestial body that orbits a star and is not massive enough to trigger nuclear fusion in its core. Sub-brown dwarfs, on the other hand, are objects that are larger than planets but smaller than brown dwarfs, which are themselves considered failed stars.

One key difference between planets and sub-brown dwarfs is their formation. Planets are believed to form through a process of accretion, where small particles in a protoplanetary disk come together to form larger bodies. Sub-brown dwarfs, on the other hand, are thought to form through the gravitational collapse of a gas cloud, similar to the way that stars form.

Another difference between planets and sub-brown dwarfs is their composition. Planets are typically composed of rock, metal, or ice, while sub-brown dwarfs are composed of gas and dust, like brown dwarfs and stars.

Finally, planets and sub-brown dwarfs differ in their behavior. Planets are typically stable and do not undergo significant changes over their lifetimes. Sub-brown dwarfs, on the other hand, may experience significant changes as they age, including the development of an atmosphere and the potential for ongoing nuclear fusion in their cores.