We present metallicity estimates for seven open clusters based on spectrophotometric indices from moderate-resolution spectroscopy .
Observations of field giants of known metallicity provide a correlation between the spectroscopic indices and the metallicity of open cluster giants .
We use \chi ^ { 2 } analysis to fit the relation of spectrophotometric indices to metallicity in field giants .
The resulting function allows an estimate of the target-cluster giants ’ metallicities with an error in the method of \pm 0.08 dex .
We derive the following metallicities for the seven open clusters : NGC 1245 , [ m/H ] = -0.14 \pm 0.04 ; NGC 2099 , [ m/H ] = +0.05 \pm 0.05 ; NGC 2324 , [ m/H ] = -0.06 \pm 0.04 ; NGC 2539 , [ m/H ] = -0.04 \pm 0.03 ; NGC 2682 ( M67 ) , [ m/H ] = -0.05 \pm 0.02 ; NGC 6705 , [ m/H ] =+0.14 \pm 0.08 ; NGC 6819 , [ m/H ] =-0.07 \pm 0.12 .
These metallicity estimates will be useful in planning future extra-solar planet transit searches since planets may form more readily in metal-rich environments .