  We present a library of Utrecht echelle spectrograph (UES) observations of a
sample of F, G, K and M field dwarf stars covering the spectral range from 4800
AA to 10600 AA with a resolution of 55000. These spectra include some of the
spectral lines most widely used as optical and near-infrared indicators of
chromospheric activity such as H_beta, Mg I b triplet, Na I D_1, D_2, He I D_3,
H_alpha, and Ca II IRT lines, as well as a large number of photospheric lines
which can also be affected by chromospheric activity. The spectra have been
compiled with the aim of providing a set of standards observed at
high-resolution to be used in the application of the spectral subtraction
technique to obtain the active-chromosphere contribution to these lines in
chromospherically active single and binary stars. This library can also be used
for spectral classification purposes. A digital version with all the spectra is
available via ftp and the World Wide Web (WWW) in both ASCII and FITS formats.
