Dispersion among the light elements is common in globular clusters (GCs),
while dispersion among heavier elements is less common. We present detection of
r-process dispersion relative to Fe in 19 red giants of the metal-poor GC M92.
Using spectra obtained with the Hydra multi-object spectrograph on the WIYN
Telescope at Kitt Peak National Observatory, we derive differential abundances
for 21 species of 19 elements. The Fe-group elements, plus Y and Zr, are
homogeneous at a level of 0.07-0.16 dex. The heavy elements La, Eu, and Ho
exhibit clear star-to-star dispersion spanning 0.5-0.8 dex. The abundances of
these elements are correlated with one another, and we demonstrate that they
were produced by r-process nucleosynthesis. This r-process dispersion is not
correlated with the dispersion in C, N, or Na in M92, indicating that r-process
inhomogeneities were present in the gas throughout star formation. The
r-process dispersion is similar to that previously observed in the metal-poor
GC M15, but its origin in M15 or M92 is unknown at present.Comment: Accepted for publication in the Astronomical Journal (22 pages, 12
figures). v2: references update
