We have obtained spectra for 1273 stars using the 0.9 m coudé feed telescope at Kitt Peak National Observatory. This telescope feeds the coudé spectrograph of the 2.1 m telescope. The spectra have been obtained with the no. 5 camera of the coudé spectrograph and a Loral 3K ; 1K CCD. Two gratings have been used to provide spectral coverage from 3460 to 9464 8, at a resolution of $1 8 FWHM and at an original dispersion of 0.44 8 pixel À1 . For 885 stars we have complete spectra over the entire 3460 to 9464 8 wavelength region (neglecting small gaps of less than 50 8), and partial spectral coverage for the remaining stars. The 1273 stars have been selected to provide broad coverage of the atmospheric parameters T eff , log g, and [Fe/H], as well as spectral type. The goal of the project is to provide a comprehensive library of stellar spectra for use in the automated classification of stellar and galaxy spectra and in galaxy population synthesis. In this paper we discuss the characteristics of the spectral library, viz., details of the observations, data reduction procedures, and selection of stars. We also present a few illustrations of the quality and information available in the spectra. The first version of the complete spectral library is now publicly available from the National Optical Astronomy Observatory (NOAO) via ftp and http.

Context. Empirical libraries of stellar spectra play an important role in different fields. For example, they are used as reference for the automatic determination of atmospheric parameters, or for building synthetic stellar populations to study galaxies. The CFLIB (Coudé-feed library, Indo-US) database is at present one of the most complete libraries, in terms of its coverage of the atmospheric parameters space (T eff , log g and [Fe/H]) and wavelength coverage 3460-9464 Å at a resolution of ∼1 Å FWHM. Although the atmospheric parameters of most of the stars were determined from detailed analyses of high-resolution spectra, for nearly 300 of the 1273 stars of the library at least one of the three parameters is missing. For the others, the measurements, compiled from the literature, are inhomogeneous. Aims. In this paper, we re-determine the atmospheric parameters, directly using the CFLIB spectra, and compare them to the previous studies. Methods. We use the ULySS program to derive the atmospheric parameters, using the ELODIE library as a reference. Results. Based on comparisons with several previous studies we conclude that our determinations are unbiased. For the 958 F, G, and K type stars the precision on T eff , log g, and [Fe/H] is respectively 43 K, 0.13 dex and 0.05 dex. For the 53 M stars they are 82 K, 0.22 dex and 0.28 dex. And for the 260 OBA type stars the relative precision on T eff is 5.1%, and on log g, and [Fe/H] the precision is respectively 0.19 dex and 0.16 dex. These parameters will be used to re-calibrate the CFLIB fluxes and to produce synthetic spectra of stellar populations.