The Integrated Photometry of Globular Clusters in the Vilnius Photometric System

K. Zdanavičius, V. Straižys
1980 Symposium - International astronomical union  
Thirty-three globular clusters of our Galaxy were observed with the filters of the Vilnius photometric system UPXYZVS with 3450, 3740, 4050, 4660, 5160, 5440, 6550 å filters (Straižys 1977). For the classification of clusters in metallicities the reddening-free parameters QUYVQPYVand QXYVcan be used. In Figure 1 these Q parameters, having a range of variation of the order of 0.4, are plotted against metallicity values from Kukarkin (1974). The parameter QPYZhas an even larger range of variation
more » ... (of the order of 0.6). For determination of color excesses of clusters every color index can be used if its intrinsic values for a given metallicity defined by quantities Q are known (Figure 2). Average color excesses determined from the diagrams QUYV, (Y-V)o; QPYV, (Y-V)oand QXYV(Y-V)oand transformed to EB-Vin Figure 3 are compared with color excesses from Kukarkin (1974). To summarize, the Vilnius system presents a number of metallicity sensitive, reddening-free parameters which can be used for [Fe/H] and color-excess determinations of globular clusters.
doi:10.1017/s0074180900092457 fatcat:igwpb5mfejcfnl7yz2mbwqek3i