astroscope
/ˈastrə(ʊ)skəʊp/noun
Originally: any of several instruments for assisting an observer in identifying stars and constellations, specifically one consisting of a pair of inscribed cones. In recent use: an instrument for observing stars; an astronomical telescope.
Origin
Late 17th century; earliest use found in Edward Sherburne (d. 1702), translator and poet. From astro- + -scope.