{"ID":5471069,"CreatedAt":"2026-07-01T07:52:19.047308345Z","UpdatedAt":"2026-07-11T22:15:17.003576626Z","DeletedAt":null,"paper_url":"https://arxiv.org/abs/1207.2451","arxiv_id":"1207.2451","title":"NLTE analysis of Sr lines in spectra of late-type stars with new R-matrix atomic data","abstract":"We investigate statistical equilibrium of neutral and singly-ionized strontium in late-type stellar atmospheres. Particular attention is given to the completeness of the model atom, which includes new energy levels, transition probabilities, photoionization and electron-impact excitation cross-sections computed with the R-matrix method. The NLTE model is applied to the analysis of Sr I and Sr II lines in the spectra of the Sun, Procyon, Arcturus, and HD 122563, showing a significant improvement in the ionization balance compared to LTE line formation calculations, which predict abundance discrepancies of up to 0.5 dex. The solar Sr abundance is log A = 2.93 \\pm 0.04 dex, in agreement with the meteorites. A grid of NLTE abundance corrections for Sr I and Sr II lines covering a large range of stellar parameters is presented.","url_abs":"https://arxiv.org/abs/1207.2451v1","url_pdf":"https://arxiv.org/pdf/1207.2451v1","authors":"M. Bergemann, C. J. Hansen, M. Bautista, G. Ruchti","published":"2012-07-10T19:47:25Z","has_code":false}