In memoriam Johann Dorschner (1938-2020)
We, the colleagues of the Astrophysical Institute and University Observatory (AIU), mourn the unexpected death of Dr. Johann ("Hans") Dorschner, the late head of our Laboratory Astrophysics group.
Hans Dorschner was one of the pioneers of cosmic-dust research. Together with his colleagues at AIU Jena, he developed, at the end of the 1960s, the idea of interstellar dust particles based on silicates and silicon carbide, which was later confirmed by astronomical IR spectroscopy. Being a profound expert in meteorites and attracted all his life to minerals, he conducted first laboratory experiments with analog materials of cosmic dust in collaboration with chemists and physicists in and around Jena, which were dedicated to the interpretation of observational infrared spectra.
Several years later, he had the opportunity to lead a chemical and spectroscopic laboratory at AIU Jena, which he did with great
success until his retirement in 2004. Together with Thomas Henning and a number of young researchers, to whom he forwarded a lot of his great knowledge and experience, he was able to contribute major pieces of research to the understanding of astronomical dust observations, based on lab work.
Hans Dorschner is the author of many excellent and well-cited articles on the spectral properties of cosmic dust analogs. The optical data derived by his group are used in many simulations of infrared spectra of AGB stars, protoplanetary disks, and interstellar clouds worldwide. However, Hans' philosophy was to always give equal attention to describing and understanding the objects of the measurement, i.e. the mineral species and glasses with their chemical and physical structure.
This he conveyed to us, his younger colleagues, besides teaching us astronomy, space research, and his knowledge on cosmic dust. At the same time, he was very active in public outreach, frequently giving public talks, writing popular astronomy books and having edited the popular journal "Die Sterne" in the 1980s (with J. Gürtler). We will always remember his talks on astronomical aspects of Christmas, for instance. Even after his active professional life, he was interested in the progress in the fields that he had initiated and continued discussing with us.
We will always remember his scientific legacy and him as an open-hearted and sincere person, and be thankful for having been his colleagues. With Hans Dorscher we not only lose a colleague, but also a mentor and good friend.