Mohammad Heydari-Malayeri left us on March 1, 2023.
Born in Malâyer (Iran), in 1947, he obtained a PhD in Astrophysics at the Observatory of Paris in 1979, and his Habilitation degree in 1983. From 1985 to 1992, he was astronomer at ESO-La Silla.
He became a specialist in the study of compact objects with high excitation in the Magellanic Clouds. Back in France, at the Observatory of Paris, he continued his work with the Hubble Space Telescope, then with the Very Large Telescope. Fascinated by the Magellanic Clouds, he studied in details the star formation regions, which are spectacular in these dwarf galaxies with low metallicity. Spectral analyses allowed him to estimate the abundances of various elements, and to perform comparison with the gaseous content, and to estimate the efficiency of stellar formation. He was particularly interested in the formation of extremely massive stars, which are very rare except in dwarf galaxies. His perseverance succeeded in solving a long-debated problem on the possibility of having stars of thousands of solar masses. The high angular resolution provided by the HST allowed him to resolve these supposedly super-massive stars and to break them down into OB star clusters.
With an interest in linguistics, he developed an Etymological Dictionary of Astronomy and Astrophysics which became the IAU Dictionary of Astronomical Concepts (https://dictionary.obspm.fr/). More than 10 000 words are explained, and he proposed translations in French and Persian for each.
He always responded with infinite kindness to requests for interviews and public appearances. He spoke regularly on the Persian channel of the BBC where he defended the scientific approach and attacked obscurantism. His vast culture and his great human qualities will be greatly missed. |