High resolution spectroscopy over 8500-8750 Å for GAIA^*,**,***

I. Mapping the MKK classification system

¹ Osservatorio Astronomico di Padova, Sede di Asiago, I-36012 Asiago (VI), Italy e-mail: munari@pd.astro.it
² Centro Interpardimentale Studi ed Attività Spaziali (CISAS "G. Colombo"), Università di Padova, Italy
³ Osservatorio Astrofisico dell' Università di Padova, I-36012 Asiago (VI), Italy e-mail: tomasella@pd.astro.it

Send offprint request to: U. Munari

Received: 29 March 1999
Accepted: 16 April 1999

Abstract

We present an Echelle+CCD high resolution spectroscopic atlas (0.25 Å/pix dispersion, 0.43 Å FWHM resolution and 20 000 resolving power) mapping the MKK classification system over the interval 8500-8750 Å. The wavelength interval is remarkably free from telluric lines and it is centered on the near-IR triplet of Ca II, the head of hydrogen Paschen series and several strong metallic lines. The spectra of 131 stars of types between O4 and M8 and luminosity classes I through V are included in the atlas. Special care was put in maintaining the highest instrumental homogeneity over the whole set of data. The capability to derive accurate MKK spectral types from high resolution observations over the interval 8500-8750 Å is discussed. The observations have been performed as part of an evaluation study of possible spectroscopic performances for the astrometric mission GAIA planned by ESA.