Named in memory of Anton Karl Thraen (1843–1902), an astronomer and catholic priest in the German district of Eichsfeld {see planet  (442)}. In his time Thraen was one of the most versatile and successful computers of orbits and ephemerides, for both comets and minor planets. Many of his articles are published in the A.N., and he also participated in the publication of the B.A.J. He was the first to show that the hyperbolic orbits of some comets are due to planetary perturbations. (M 15091) _ _.