Astron. Astrophys. Suppl. Ser. 142, 339-345

Automatic extraction and classification of low-dispersion objective prism stellar spectra

E. Bratsolis^1,2 - I. Bellas-Velidis¹ - A. Dapergolas¹ - E. Kontizas¹ - M. Kontizas²

Send offprint request: E. Bratsolis
e-mail: ebrats@atlas.uoa.gr

1 - Astronomical Institute, National Observatory of Athens, P.O. Box 20048, GR-11810 Athens, Greece
2 - Section of Astrophysics, Astronomy and Mechanics, Department of Physics, University of Athens, GR-15784 Athens, Greece

Received July 22; accepted November 16, 1999

Abstract:

The observing material used for this task is prism spectral plates taken with Schmidt-class telescopes. Such a plate generally contains thousands of spectra, and there are prism-plate libraries and digitized databases in several astronomical centers that can be exploited for this analysis. After a successive detection from the prism plate image, the spectra are automaticaly extracted in one-dimensional streams containing all the basic information. These spectra require automated classification methods to be analyzed in an objective form. In this article we compare two classification methods directly applied to stellar spectra: a linear correlation and a minimum distance method.

Key words: methods: data analysis -- stars: fundamental parameters