Astronomers Urbain Le Verrier, John Couch Adams and Johann Gottfried Galle collaborate on the discovery of Neptune.

Urbain Le Verrier
Urbain Jean Joseph Le Verrier was a French astronomer and mathematician who specialized in celestial mechanics and is best known for predicting the existence and position of Neptune using only mathematics.
John Couch Adams
John Couch Adams was a British mathematician and astronomer. He was born in Laneast, near Launceston, Cornwall, and died in Cambridge.
Johann Gottfried Galle
Johann Gottfried Galle was a German astronomer from Radis, Germany, at the Berlin Observatory who, on 23 September 1846, with the assistance of student Heinrich Louis d'Arrest, was the first person to view the planet Neptune and know what he was looking at. Urbain Le Verrier had predicted the existence and position of Neptune, and sent the coordinates to Galle, asking him to verify. Galle found Neptune in the same night he received Le Verrier's letter, within 1° of the predicted position. The discovery of Neptune is widely regarded as a dramatic validation of celestial mechanics, and is one of the most remarkable moments of 19th-century science.
Discovery of Neptune
The planet Neptune was mathematically predicted before it was directly observed. With a prediction by Urbain Le Verrier, telescopic observations confirming the existence of a major planet were made on the night of September 23–24, Autumnal Equinox of 1846, at the Berlin Observatory, by astronomer Johann Gottfried Galle, working from Le Verrier's calculations. It was a sensational moment of 19th-century science, and dramatic confirmation of Newtonian gravitational theory. In François Arago's apt phrase, Le Verrier had discovered a planet "with the point of his pen".