An Abundance Analysis of Two S Stars at High Galactic Latitude

We present abundances of Ti, Fe, and Ni as well as 10 post–iron‐peak elements in two Galactic S stars, S UMa and Stephenson 1303. Based upon the presence or absence of Tc in their spectra, S UMa is an intrinsic S star and Stephenson 1303 is an extrinsic S star. Both stars are slightly metal‐poor and at high Galactic latitude; they thus make an interesting comparison as well as a further test of current models of nucleosynthesis in low‐mass stars. In addition, the abundance ratio of heavy to lights‐process elements, [hs/ls], correlates with the metallicities of Stephenson 1303 and S UMa as expected if the13C neutron source drives thes‐process.