Red Supergiants ( RSGs ) are among the brightest stars in the local universe , making them ideal candidates with which to probe the properties of their host galaxies .
However , current quantitative spectroscopic techniques require spectral resolutions of R \mathrel { \hbox { \hbox to 0.0 pt { \hbox { \lower 4.0 pt \hbox { $ \sim$ } } } \hbox { $ > $ } } } 17,000 , making observations of RSGs at distances greater than 1Mpc unfeasible .
Here we explore the potential of quantitative spectroscopic techniques at much lower resolutions , R \approx 2-3000 .
We take archival J -band spectra of a sample of RSGs in the Solar neighbourhood .
In this spectral region the metallic lines of Fe i , Mg i , Si i  and Ti i  are prominent , while the molecular absorption features of OH , H _ { 2 } O , CN and CO are weak .
We compare these data with synthetic spectra produced from the existing grid of model atmospheres from the MARCS project , with the aim of deriving chemical abundances .
We find that all stars studied can be unambiguously fit by the models , and model parameters of \log g , effective temperatures T _ { eff } , microturbulence and global metal content may be derived .
We find that the abundances derived for the stars are all very close to Solar and have low dispersion , with an average of \log Z =0.13 \pm 0.14 .
The values of T _ { eff } Â fit by the models are \sim 150K cooler than the stars ’ literature values for earlier spectral types when using the Levesque et al .
temperature scale , though we find that this discrepancy may be reduced at spectral resolutions of R = 3000 or higher .
In any case , the temperature discrepancy has very little systematic effect on the derived abundances as the equivalent widths ( EWs ) of the metallic lines are roughly constant across the full temperature range of RSGs .
Instead , elemental abundances are the dominating factor in the EWs of the diagnostic lines .
Our results suggest that chemical abundance measurements of RSGs are possible at low- to medium-resolution , meaning that this technique is a viable infrared-based alternative to measuring abundance trends in external galaxies .