SIMBAD references

We present revised positions for the 1051 galaxies belonging to the Karachentseva Catalog of Isolated Galaxies (CIG). New positions were calculated by applying SExtractor to the Digitized Sky Survey CIG fields with a spatial resolution of 1.2". We visually checked the results and for 118 galaxies had to recompute the assigned positions due to complex morphologies (e.g. distorted isophotes, undefined nuclei, knotty galaxies) or the presence of bright stars. We found differences between older and newer positions of up to 38" with a mean value of 2.96" relative to SIMBAD and up to 38" and 2.42" respectively relative to UZC. Based on star positions from the APM catalog we determined that the DSS astrometry of five CIG fields has a mean offset in (α, δ) of (-0.90", 0.93") with a dispersion of 0.4". These results have been confirmed using the 2MASS All-Sky Catalog of Point Sources. The intrinsic errors of our method combined with the astrometric ones are of the order of 0.5".