  This paper is dedicated to the discovery of one of the most important
relationships in supernova cosmology - the relation between the peak luminosity
of Type Ia supernovae and their luminosity decline rate after maximum light.
The history of this relationship is quite long and interesting. The
relationship was independently discovered by the American statistician and
astronomer Bert Woodard Rust and the Soviet astronomer Yury Pavlovich Pskovskii
in the 1970s. Using a limited sample of Type I supernovae they were able to
show that the brighter the supernova is, the slower its luminosity declines
after maximum. Only with the appearance of CCD cameras could Mark Phillips
re-inspect this relationship on a new level of accuracy using a better sample
of supernovae. His investigations confirmed the idea proposed earlier by Rust
and Pskovskii.
