Table of Contents
ISRN Astronomy and Astrophysics
Volume 2011 (2011), Article ID 127030, 9 pages
Research Article

Luminosity Function of Some Open Clusters

1Departement of Astronomy, National Research Institute of Astronomy and Geophysics (NRIAG), Cairo 11421, Egypt
2Department of Physics, Faculty of Science, Northern Border University, Arar 1321, Saudi Arabia
3Department of Mathematics, Qassim University, Qassim 51452, Saudi Arabia

Received 11 January 2011; Accepted 21 February 2011

Academic Editors: G. Chernov and M. Marconi

Copyright © 2011 W. H. Elsanhoury et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


We investigated the luminosity function (LF) and initial mass function (IMF) of some open clusters having different ages. To calculate the LF, we followed the classical definition by van Rhijn (1936). Statistical investigation of the dispersion around a range of magnitudes concerning what is called Wielen dip revealed that the dip is unreal. To confirm the unreality of the dip, we computed the IMF for these open clusters, the statistical investigation of the IMF confirmed the results obtained using the LF, that is, there is no dip for these open clusters under study.