Abstract
The observed abundances in the Cas A supernova remnant (SNR) are used together with the results of evolutionary calculations of massive stars to construct an evolutionary picture for the Cas A progenitor star. From the structure shown by the remnant, it is believed that the precursor star was a WR with a lifetime of 10^4 years. With this assumption and the chemical abundances produced during the stellar nucleosynthesis we present results which suggest that the precursor of Cas A was a star with a mass between 29-30 M[ scriptstyle sun ]on the ZAMS.
