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.
Vahe Gurzadyan
He identified the Halley's comet depicted on ancient coins of Armenian king Tigranes the Great, I c.BC. as the earliest known image of that comet He revealed the observation of supernova SN 1054 (progenitor of Crab nebula) in Armenian medieval chronicle of Hetum (Hayton of Corycus) and Cronaca Rampona.