Werner Landgraf
He also developed a method of eliminating systematic errors in positioning brighter comets that resulted in a more accurate prediction of the Halley's Comet. A recalculation of the path of Halley's comet to 2317 BC confirmed that the Greeks had already seen the comet on 466 B.C.
He discovered seven minor planets including 3683 Baumann, 4378 Voigt (named after Hans-Heinrich Voigt), 9938 Kretlow and 4349 Tibúrcio at ESO's La Silla Observatory in northern Chile.
Yale University Observatory
Yale's first observatory, the Atheneum, was founded in 1830, situated in a tower. From 1830 it housed Yale's first refractor, a Dollond donated by Sheldon Clark. It was the largest in the United States at the time. With this telescope Olmsted and Elias Loomis made the first American sighting of the return of Halley's Comet in 1835. (August 31; seen in Europe August 6, but no news of this had reached America). The telescope was mounted on casters and moved from window to window, but it could not reach altitudes much over 30 deg above the horizon.