What is "leoniders"

Leoniders (леонидяне) are a fictional alien race from the Noon Universe created by the Strugatsky brothers. Their homeworld is Leonida (Леонида), a planet discovered in 2133 AD by Leonid Gorbovsky.

Leoniders are mentioned in "Noon: 22nd Century", " An Attempt to Escape" and " Beetle in an Anthill".