We present an empirical stellar spectra library created using spectra from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope ( LAMOST ) DR5 .
This library represents a uniform data set ranging from 3750 through 8500 K in effective temperature ( T _ { eff } ) , from -2.5 through +1.0 dex in metallicity ( [ Fe/H ] ) , and from 0 to 5.0 dex in gravity ( log g ) .
The spectra in the library have resolution R \sim 1800 , with well–calibrated fluxes and rest–framed wavelengths .
Using a large number of red stars observed by LAMOST , we generated denser K type templates to fill in data missing from current empirical spectral libraries , particularly the late K type .
For K giants , we calibrated the spectroscopic surface gravities against the asteroseismic surface gravities .
To verify the reliability of the parameters labeled for this library , we performed an internal cross-validation by using a \chi ^ { 2 } minimization method to interpolate parameters of each individual spectrum using the remaining spectra in the library .
We obtained precisions of 41 K , 0.11 dex , and 0.05 dex for T _ { eff } , log g , and [ Fe/H ] , respectively , which means the templates are labeled with correct stellar parameters .
Through external comparisons , we confirmed that measurements of the stellar parameters through this library can achieve accuracies of approximately 125K in T _ { eff } , 0.1 dex in [ Fe/H ] and 0.20 dex in log g without systematic offset .
This empirical library is useful for stellar parameter measurements because it has large parameter coverage and full wavelength coverage from 3800 to 8900 Å .