Cluster analysis; Dimensionality reduction; H-R diagram; Harvard spectral classification

This article aims to analyse main sequence stars of the Hertzsprung-Russell diagram using cluster analysis methods in order to prove if the results from the cluster analysis will match with Harvard spectral classification. Nextdo a dimensional reduction task in order to see if it is possible to explain the variance of the data using less factors than examined numbers of parameters. Using particular stars' parameters following methods are performed: hierarchical clustering, centroid-based clustering (k-means), principal component analysis and factor analysis.