I'm trying to think of a good word for an asteroid/planetoid that has no stable orbit but has been ejected from a system and is passing close to a sun. Any help?
See nnnnnn's comment below.
The NASA website, describing 'oumuamuam, uses the term "interstellar object." Extrasolar asteroid would seem to be another option. I haven't seen a unique word different from asteroid that originated outside of the solar system.
It seems a simple prefix is sufficient to describe objects beyond the solar system, i.e. exoplanet.
Scienfitic American has an article which uses the term "interstellar object."
Also, see answers to: