Wolf diagram
The Wolf Diagram is a stellar statistical tool named after the German astronomer Max Wolf for determining the distance and extent of stellar dark clouds .
In the Wolf diagram, the star number N is plotted against its apparent brightness m . The comparison of the theoretically expected N - m curve with the empirically determined curve results in a difference Δm , the so-called interstellar extinction . The interstellar extinction usually begins at a value m 1 and is fully pronounced at m 2 . The distance and extent of stellar dark clouds result from the values of m 1 and m 2 .
literature
Klaus Lindner: Pocket Book of Astronomy. Specialized book publisher Leipzig-Cologne 1993.