Resulting observed Phoenix spectrum

(a) Resulting observed Phoenix spectrum (red points) of 30 July 2003, and model line profile of [Al VI]; in grey, model profile of Al-26 had it been present at an isotope ratio of 1. In (b), co-added spectrum (red points). Light dotted-line does not include electric-quadrupole hyperfine splitting. The inclusion of the electric quadrupole hyperfine terms improves the fit (solid grey line). The original Phoenix spectra were obtained at a spectral resolution of 75,000.