High-dispersion spectra of 333 stars in the open cluster NGC 6819 , obtained using the HYDRA spectrograph on the WIYN 3.5m telescope , have been analyzed to determine the abundances of iron and other metals from lines in the 400 Å region surrounding the Li 6708 Å line .
Our spectra , with signal-to-noise per pixel ( SNR ) ranging from 60 to 300 , span the luminosity range from the tip of the red giant branch to a point two magnitudes below the top of the cluster turnoff .
We derive radial and rotational velocities for all stars , as well as [ Fe/H ] based on 17 iron lines , [ Ca/H ] , [ Si/H ] , and [ Ni/H ] in the 247 most probable , single members of the cluster .
Input T _ { eff } estimates for model atmosphere analysis are provided by ( B - V ) colors merged from several sources , with individual reddening corrections applied to each star relative to a cluster mean of E ( B - V ) = 0.16 .
Extensive use is made of ROBOSPECT , an automatic equivalent width measurement program ; its effectiveness on large spectroscopic samples is discussed .
From the sample of likely single members , [ Fe/H ] = -0.03 \pm 0.06 , where the error describes the median absolute deviation about the sample median value , leading to internal precision for the cluster below 0.01 dex .
The final uncertainty in the cluster abundance is therefore dominated by external systematics due to the temperature scale , surface gravity , and microturbulent velocity , leading to [ Fe/H ] = -0.02 \pm 0.02 for a sub-sample restricted to main sequence and turnoff stars .
This result is consistent with our recent intermediate-band photometric determination of a slightly subsolar abundance for this cluster .
[ Ca/Fe ] , [ Si/Fe ] , and [ Ni/Fe ] are determined to be solar within the uncertainties .
NGC 6819 has an abundance distribution typical of solar metallicity thin disk stars in the solar neighborhood .