High-resolution spectroscopy of the hot Am star HR 3383

Abstract

ABSTRACT We present the spectrum analysis of the hot Am star HR 3383 (A1 Vm). Hubble Space Telescope STIS and Nordic Optical Telescope SOFIN data are modelled with synthetic spectra, and abundances are investigated for 78 elements. Most light elements up through oxygen show deficiencies, compared to solar abundances, followed by the general trend of increasing abundance enhancement with atomic number that levels off at a 30-fold enhancement at the lanthanide group and heavier elements. The derived element distribution is generally consistent with what is observed in other hot Am stars. Abundances for HR 3383 are also similar to what is seen for the cooler HgMn stars, with the exception of the platinum-group elements that generally show dramatic enhancements in the HgMn stars. Current theory and calculations are able to predict most observed abundances and abundance trends through the iron group. The large number of derived element abundances in this study provides a constraint for theoretical calculations attempting to explain the heavy element abundances in chemically peculiar stars. This paper includes a comprehensive description of spectral lines useful for an abundance analysis of late B and A type stars, and comments are provided on the atomic data. New data for hyperfine structure components for three lines in Lu iii and a single line in Lu ii are presented, based on laboratory spectra. In addition to the stellar spectrum, lines from the interstellar medium are noted for several of the strongest Fe ii ultraviolet transitions.