Elemental abundances in the inner galaxy open cluster M11

We report on the results of our analyses of high-quality spectra of 10 bright K giants in the young cluster M11. We derive a mean [Fe/H] value of 0.10 and a mean temperature near 4500 K. There is a wide range in the Li abundances, from [Li/Fe] < -0.6 to +0.8. The C-12/C-13 ratio ranges from 14 to 22. Na and Al show excesses of 0.21 and 0.20, respectively. There is some scatter among the alpha-elements, Si, Ca, and Ti, of uncertain reality. A significant deficiency of Ni, [Ni/Fe] = -0.32 +/- 0.10(s.d.), was found. For the heavy elements, we find La/Eu to be enhanced, indicating a larger ratio of s/r-process contribution in the M11 stars as compared with the Sun. With the exception of Li, C-12/C-13, and possibly Na, these differences from solar abundance are due to differences in the material out of which M11 formed.