The Bismuth Abundance in the HgMn Stars chi) Lupi and HR7775 and Improved Atomic Data for Selected Transitions of Bi I, Bi II, and Bi III

Published

April 1, 2001

Author(s)

G Wahlgren, T Brage, J C. Brandt, J Fleming, S Johansson, D S. Leckrone, C R. Proffitt, Joseph Reader, Craig J. Sansonetti

Abstract

High resolution spectra of the chemically peculiar HgMn type stars Χ Lupi and HR7775 obtained with the Hubble Space Telescope/Goddard High Resolution Spectrograph are investigated for their abundance of bismuth. HR7775, previously known from International Ultraviolet Explorer (IUE) spectra to display strong lines of Bi II, is determined to have bismuth present at an enhancement level of [Bi/H] = +4.8 dex from the lines Bi II λλ1436, 1902 and +4.3 from fitting the wings of the hyperfine structure components of Bi III λ1423 . The bisnuth enhancement for Χ Lupi is found to be near a level of +1.5 dex. An ionization anomaly between Bi⁺ and Bi²+ is apparent for Χ Lupi and possibly for HR7775. New laboratory measurements for wavelengths and hyperfine structure patterns of Bi I/II/II lines are presented, as well as the results of calculations for hyperfine structure constants and oscillator strengths for select lines of Bi II and Bi III.

Citation

Astrophysical Journal

Volume

551

Issue

No. 1

Pub Type

Journals

Keywords

atomic spectra, bismuth, chemically peculiar stars, hyperfine structure, oscillator strengths, wavelengths

Citation

Wahlgren, G. , Brage, T. , Brandt, J. , Fleming, J. , Johansson, S. , Leckrone, D. , Proffitt, C. , Reader, J. and Sansonetti, C. (2001), The Bismuth Abundance in the HgMn Stars {chi) Lupi and HR7775 and Improved Atomic Data for Selected Transitions of Bi I, Bi II, and Bi III, Astrophysical Journal (Accessed October 9, 2024)