This element was discovered by W. Ramsay and W. Travers in London in 1898. Its name comes from the Greek xenos (stranger).
Ionization energies
XeI 12.1 eV, XeII 21.2 eV, XeIII 32.1 eV.
Behavior in stars
No Xe lines have been observed in the sun.
XeII was found by Bidelman (1962b, 1966) in two Ap stars of the Hg-Mn subgroup. Adelman (1987) measured W(4415) = 0.009 for XeII and Adelman (1992) found W(4603) = 0.016. Jaschek and Brandi (1972) found Xe in one star of the Cr-Eu-Sr subgroup. See also Andersen et al. (1984).
Isotopes
Xe has six stable isotopes, namely Xe 129, 130, 131, 132, 134 and 136, which
occur in the solar system with 27%, 4%, 21%, 27%, 10% and 9% abundances
respectively. There exist also 25 short-lived isotopes and isomers.
Origin
Xe can be produced by the r, s and p processes. Xe130 is an
process product, Xe 129, 131, 134 and 136 are pure r products and
Xel32 can be produced by either the r process or the s process.
Published in "The Behavior of Chemical Elements in Stars", Carlos Jaschek and Mercedes Jaschek, 1995, Cambridge University Press.