Accurate Positions of Radio Sources at 408 MHz

Abstract

The Molonglo radio telescope has been used to measure positions and flux densities for 314 small-diameter radio sources between declinations of + 19° and −80°. The mean estimated errors in position are less than |${1}^{\prime{}\prime}\cdot5$| in right ascension and |${2}^{\prime{}\prime}\cdot0$| in declination; this accuracy is confirmed by a limited series of comparisons with precise interferometer positions. A large fraction of previously suggested southern identifications is not supported by the more accurate radio positions. Source extensions are found in 25 per cent of the listed sources by application of a sensitive method for detecting the direction of elongation.