A library of 0.5 to 2.5 mu m spectra of luminous cool stars

We present a library of 0.5 - 2.5 mum digital spectra of cool, mostly varia ble, giant and supergiant stars which should be useful for spectral synthes is applications, as well as for comparison with theoretical model atmospher e calculations. The library includes carbon stars. Galactic Bulge and Magel lanic Cloud stars, and OH/IR stars. The stars observed cover a range of metallicities and masses. Most variable objects were observed several times, at different phases of their pulsatio n cycle. We discuss the effects of various fundamental parameters and of va riability on the spectra. Based on period-luminosity relations and stellar evolutionary tracks, we tentatively assign initial masses to each object.