exomoon

plural exomoons

1. astronomyA moon that is outside the Solar System (our solar system).

   Now we get exoplanets, dwarf planets, rogue planets, and (exo)moons. That's ok, but then comes the utter silliness: none of them are planets. Even those bigger than Jupiter aren't planets.

   2006 August 27, Jens Egon Nyborg, “Re: It's official--Jupiter is now a dwarf planet!”, in rec.arts.sf.written,rec.arts.sf.science (Usenet), retrieved 20 Mar 2019, message-ID <xweIg.30$fR6.17@news.get2net.dk>

   1 more example

   Of course we can't detect exomoons now (or for a long while), but could planets like 51 Peg b have any moons? Wouldn't the star strip them off? I don't suppose there can be a moon around a planet that orbits in more time than it takes that planet to orbit its star.

   2001 July 14, Robert Casey, “Moons around "hot Jupiter" exoplanets, possible?”, in sci.astro.research (Usenet), retrieved 20 Mar 2019, message-ID <mt2.0-23734-995099843@star.bris.ac.uk>

   Synonyms: extrasolar moon, exosolar moon