Astre is a French word that means “celestial body" or "heavenly body”. Astre is a word of or relating to the astronomical objects. It can designate a star as much as it can refer to a planet, or the sun and the moon - pretty much anything that shines in the night sky.
Mondsüchtig (German) is a person that is addicted to the night and especially looking at the moon. (added by herbsttaucher)