paraselene
noun·/ˌpær.ə.səˈliː.ni/
A bright spot or "mock moon" appearing beside the moon, typically as part of a halo display in ice-crystal clouds. Moonlight refracted into a secondary apparition. A paraselene stands apart from the halo that encircles, a companion light that looks like an echo.
Two pale paraselenae hovered on either side of the moon, as if night had grown parentheses of light.
Etymology
From Greek para- "beside" + selēnē "moon." Diagrammatic: it tells you where to look, next to the moon, not at it.
Related Words
parheliona “sun dog,” the solar analogue
halothe broader optical phenomenon
cirrostratuscloud type often associated with halos
refractionthe physical mechanism behind the sight