Using the NIRSPEC spectrograph at Keck II , we have obtained H and K -band echelle spectra for a young ( \sim 10 - 15 Myr ) , luminous ( M _ { V } \sim - 13.2 ) super-star cluster in the nearby spiral galaxy NGC 6946 .
From spectral synthesis and equivalent width measurements we obtain for the first time accurate abundances and abundance patterns in an extragalactic super-star cluster .
We find [ Fe/H ] = -0.45 \pm 0.08 dex , an average \alpha -enhancement of \approx + 0.22 \pm 0.1 dex , and a relatively low ^ { 12 } C / ^ { 13 } C \approx 8 \pm 2 isotopic ratio .
We also measure a velocity dispersion of \approx 9.1 km/s , in agreement with previous estimates .
We conclude that integrated high-dispersion spectroscopy of massive star clusters is a promising alternative to other methods for abundance analysis in extragalactic young stellar populations .