Minkowski was the son of Marie Johanna Siegel and physiologist
Oskar Minkowski. His uncle was
Hermann Minkowski, a mathematician and one of Einstein's teachers in Zürich. Rudolph studied
supernovae and, together with
Walter Baade, divided them into two classes (
Type I and
Type II) based on their spectral characteristics. He and Baade also found optical counterparts to various
radio sources. He headed the
National Geographic Society – Palomar Observatory Sky Survey, a photographic atlas of the entire northern sky (and south to
declination -22°) down to an apparent
magnitude of 22. which was later quantified by
Faber and Jackson. He won the
Bruce Medal in 1961. == List of discovered astronomical objects ==