THE ABUNDANCES OF Pt, Au, AND Hg IN THE CHEMICALLY PECULIAR HgMn-TYPE STARS κ CANCRI AND χ LUPI

摘要

Echelle mode spectra obtained with the Goddard High Resolution Spectrograph onboard the Hubble Space Telescope have been used to determine the abundances of the heavy elements Pt, Au, and Hg in the chemically peculiar HgMn-type stars κ Cancri and χ Lupi. The abundances were determined by fitting observed line profiles with synthetically generated spectra and are found to be enhanced relative to solar system values by between three and five orders of magnitude in both stars. The Hg isotope mixture in κ Cancri is found to resemble the terrestrial mixture while that of χ Lupi is dominated by the heaviest isotope. As determined from multiple ionization states, the abundances place constraints upon theories attempting to explain the large sur-ficial abundances of heavy elements.