Axial Ratios, Orientations, and Center Coordinates of Galactic Globular Clusters

Extract

A program to determine the axial ratios and major axis orientations for a sample of 120 galactic globular star clusters was begun by us recently. The sample was selected from the clusters listed by Kukarkin and which can be seen on the glass copies of the blue-emulsion plates of the Palomar Observatory Sky Survey and on the B-series film copies of the European Southern Observatory Sky Survey. Out of the major program will come axial-ratios of the elliptical isodensity contours for each cluster, as well as the orientations of the major axes of the elliptical contours, and an accurate position for the center of each of the clusters in the sample. The probable errors of the central coordinates will be on the order of ±1 arcsec or better.