2025RNAAS...9...20M

Lines of once-ionized krypton, an element rarely found in stellar spectra, are sought in high resolution Ultraviolet and Visible Echelle Spectrograph spectra of the sharp-lined star HR 6000. Among the five lines of Kr II probed, the line at 4355.48 Å is clearly present. As no quantitative measurement nor computation of the oscillator strength are available for this line, only a crude estimate of the abundance of krypton can be provided. Krypton is found to be overabundant with an excess of +2.70 dex respect to the solar abundance. Eight lines of Xe II are synthesized in order to derive the abundances of xenon in the atmosphere of HR 6000 using the current atomic data in the Atomic Spectra Database at National Institute of Standards and Technology. The mean excess in xenon is found to be +4.75 dex, with a large scatter, but in fair agreement with an earlier measurement.