Abstract
The DDO 51 filter has been added to the Washington photometric system. The strong surface gravity sensitivity of the Mg I "b" triplet and MgH bands which it monitors allows the system to easily discriminate between dwarfs and giants of late G and K spectral type. The system is especially suited as a membership criterion for abundance studies of distant cluster giants. The Mg index is insensitive to surface gravity variations among G giants. The metallicity sensitivity among giants is also relatively weak. Population I and II giants can be distinguished but no further differentiation is evident.

This publication has 0 references indexed in Scilit: