Question: Percival Lowell established the observatory after what American astronomer that discovered Pluto in 1930?
Sentence (from "Elizabeth Langdon Williams"): She was the head human computer for Lowell in 1915, when her calculations led to the first captured image of Pluto, but she left the observatory before 1930 when Clyde Tombaugh finally realized the significance of this image.
Relevant evidence: No