people hypothesized that the gravity of an unseen planet was affecting Uranus orbit. by 1846, mathematical in England and France had calculated the orbit of this unseen planet. shortly thereafter an observer saw and unknown object in the predicted area of the sky. It was Neptune
From calculations based on the orbits of other planets. There was obviously something influencing the orbit of Uranus.
he used a telescope to discover Neptune
neptune
Yes. Typically one looks to the sky to view Neptune.
Neptune
Astronomers used observational and mathematical skills to discover Neptune. They observed irregularities in the orbit of Uranus and calculated the gravitational influence needed to explain these irregularities, leading them to predict and discover the existence of Neptune.
In Neptune
Neptune was discovered on September 23, 1846 by Johan Galle.
1989
Astronomers had noticed unexpected changes in the orbit of Uranus: the only explanation was another planet. Detailed study of the orbit of Uranus led to estimates about the size and location of Neptune.
William Lassell
Actually it was found by voyager 2, it's the same that discover Neptune