Carlos Jaschek died in Salamanca (Spain) on April 12th, 1999. He was born in 1926 in Brieg (then in Germany, now the Polish Brzeg), but emigrated to Argentina with his parents at the age of eleven. After graduation, he started working at La Plata Observatory as early as 1947 and obtained his PhD in Astronomy in 1952.
After returning from a one-year stay in United States (1956-1957), he was nominated Professor of Astrophysics and Director of the Astrophysics Department of La Plata University, positions he held until his departure in 1973. During this time, he developed a large number of contacts at the international level, where he became a renowed spectroscopist. He has been repeatedly invited as Associate Professor e.g. at Perkins, Yerkes, Michigan, Ohio State Observatories, all places where he developed long-term collaborations which remain active during his whole life.
Changes in the political situation in Argentina led him to leave La Plata and to move to Europe in 1973. After spending a year at Geneva Observatory, he became in 1974 Director of Centre de Données Stellaires (CDS) in Strasbourg, France (now know as Centre de Données astronomiques de Strasbourg, a component of Strasbourg Astronomical Observatory). He was also Associate Professor, then Full Professor, at the local Louis Pasteur University. In total, Carlos spent almost twenty years in Strasbourg, where he became a French citizen, before retiring and moving to Salamanca with his wife Mercedes.
In his scientific work as a leading spectroscopist and as an author of some 250 refereed publications, he dedicated many efforts to the observation and careful classification of peculiar stars. He published several atlases, catalogues, and reference books about stellar classification. He helped to stress the fundamental role that MK classification can play for the development of our understanding of the astrophysics of stars: this involved studies of `normal' or peculiar stars, and also a statistical approach of stellar populations, groups, and sub-groups.
His main contribution in this field was probably the understanding of the astrophysical nature of Be and shell stars, Ap Si4200 stars, and many groups of anomalous abundance, all these works in close collaboration with his wife Mercedes Jaschek. Determination of the fundamental properties of the Be, Ae and shell stars in the near infrared were performed until after they retired, as a collaboration with Yvette Andrillat. Carlos and Mercedes Jaschek have also been deeply involved in producing the first classification schemes in the ultraviolet (first with the TD1 S2/68 fluxes, later with the IUE low-dispersion spectra).
Carlos was an active member of the International Astronomical Union and became President of IAU Commission 45 (Spectral Classification) in 1973.
His interest in taxonomy led him to pursue a long-term collaboration with the Geneva group of Marcel Golay about the compared merits of photometry and spectroscopy for classifying stars. He was very conscious that spectral classification decided with the human eye would have soon to be replaced by new automatic methods, and encouraged many of the current developments in this area.
Carlos Jaschek played a key role in the organization of the data centres at an international level. Building up on the startup work of his predecessor Jean Jung, he will remain associated to the early developments of CDS he directed from 1974 to 1990. He was specifically sensible to the importance of organizing world-wide access to data, including third world countries. He made the CDS an internationally respected institution.
An active teacher, of wide and impressive scientific knowledge, Carlos has supervised many students. A social and courteous man, he organized an impressive number of colloquia and meetings. Many of these were the very first ones of their kind, especially those relating to data centers and focusing on innovative developments for emerging technologies: new statistical methodologies, international networks, large databases, digitized sky surveys, and so on. His book on data in astronomy, albeit slightly outdated since written before the Internet age, remains a mandatory reading for anyone tackling the field.
He was very active in the presentation of astronomy to many publics. His lectures in ethno-astronomy at Strasbourg University were for him an opportunity to create a working group `astronomy and human sciences'; these lectures were published as his last book in 1998.
The memory of Carlos Jaschek cannot be separated from the memory of his wife Mercedes, who spent her whole career as an astronomer beside him. They were very close, using to share most of their scientific work on spectroscopy of peculiar stars. Carlos was deeply affected by the loss of his wife, who died in Salamanca where they had retired, in November 1995.
Many of us will always remember the warm welcome Mercedes and Carlos Jaschek reserved for their guests, colleagues and students.
[Daniel Egret & Andre Heck, current and past directors of Strasbourg Observatory]
From left to right: A. Heck, C. Jaschek and D. Egret. This somehow historical picture has been taken (likely by Mercedes Jascheck) at the first workshop on networks in astronomy organized by CDS on 8 Nov 1985. The trophies in the background are not CDS' ones, but those of the sport club where the meeting was held.