GOLD Au Z = 79

Gold has been known since prehistory. The symbol is derived from Latin aurum (gold).

Ionization energies
AuI 9.2 eV, AuII 20.5 eV, AuIII 30.0 eV.

Absorption lines of AuI
In the sun, the equivalent width of AuI 3122(1) is 0.005.

Behavior in non-normal stars
The probable detection of Au I was announced by Jaschek and Malaroda (1970) in one Ap star of the Cr-Eu-Sr subgroup. Fuhrmann (1989) detected Au through the ultimate line of Au II at 1740(2) in several Bp stars of the Si and Ap stars of the Cr-Eu-Sr subgroups. The presence of Au seems to be associated with that of platinum and mercury.

Au has one stable isotope, Au197 and 20 short-lived isotopes and isomers.

Au can only be produced by the r process.

Published in "The Behavior of Chemical Elements in Stars", Carlos Jaschek and Mercedes Jaschek, 1995, Cambridge University Press.