Interesting lil tidbit that comes up every “supermoon” (a term I had never read until 2017, strangely enough) is “perigee-syzygy” (a particular alignment of three celestial bodies–a term I had read/heard long ago). It refers to the particular Earth-Moon system condition that results in what is apparently called a “supermoon.” *shrugs* I find “perigee-syzygy” more congenial and felicitous as a term.
BTW, you can try again on the 31st, if that’s a thing for you.