The Praesepe open cluster and the galactic distance scale

Updated proper motions for 328 probable members of the Praesepe are used to determine the distance to this open cluster by Hertzsprung's geometric method. The cluster distance was found to be r=171±15 pc, which corresponds to the distance modulus \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $$V_0 - M_V = 6\mathop .\limits^m 16 \pm 0.19$$ \end{document}. The distance scale for open clusters is discussed.