187Re,recyclingR-process elements through stars,and the age of the Galaxy

The enhanced -decay rate of ionized¹⁸⁷Re in stars has been studied within the context of a detailed numerical model of the production ofr-process elements and their recycling through stars during the course of galactic evolution. It is concluded that the enhanced decay rate does not significantly reduce the Re-Os chronometer age for the Galaxy. Consequently, the¹⁸⁷Re -decay half-life and the neutron cross-section ratio (¹⁸⁶Os)/(¹⁸⁷Os) remain as the significant uncertainties in this chronology. Unlike the uncertainties in other chronologies, both are amenable to laboratory measurements.