HD 65949: Rosetta Stone or Red Herring
Abstract
HD 65949 is a late B star with exceptionally strong Hg II at 3984[A], but it is not a typical HgMn star. The Re II spectrum is of extraordinary strength. Abundances, or upper limits are derived here for 58 elements based on a model with Teff = 13100K, and log(g) = 4.0. Even-Z elements through nickel show minor deviations from solar abundances. Anomalies among the odd-Z elements through copper are mostly small. Beyond the iron peak, a huge scatter is found. The abundance pattern of the heaviest elements resembles the N=126 r-process peak of solar material, though not in detail. We find a significant correlation of the abundance excesses with second ionization potentials for elements with Z > 30. This indicates the relevance of photospheric or near-photospheric processes. We explore a model with mass accretion of exotic material followed by the more commonly accepted differentiation by diffusion. That model leads to a number of predictions which challenge future work. Likely primary and secondary masses are near 3.3 and 1.6 M(solar), with a separation of ca. 0.25 AU. New atomic structure calculations are presented in two appendices.
Cite
@article{arxiv.1002.2945,
title = {HD 65949: Rosetta Stone or Red Herring},
author = {C. R. Cowley and S. Hubrig and P. Palmeri and P. Quinet and É. Biémont and G. M. Wahlgren and O. Schütz and J. F. González},
journal= {arXiv preprint arXiv:1002.2945},
year = {2016}
}
Comments
Accepted by MNRAS: 16 pages, 5 figures