Accuracy of binary star speckle interferometry

Abstract

AbstractNearly 400 speckle interferometric observations of binary stars with separations between 0033 to 325 obtained with the 4 meter Mayall telescope at Kitt Peak have been analyzed for accidental and systematic errors in order to determine the reliability of the error estimates assigned to single measurements and to develop schemes for correcting for possible systematic effects. The calibration technique currently in use limits the accuracy to ±0.6% of the angular separation and to ±02 in position angle. Comparison of 101 observations to published orbits of high quality gives mean residuals and r.m.s. errors of <Δθ> = -00005±00072 and <Δρ> = 00051±0158. Small systematic errors can be introduced into separation measurements unless the spatial frequency power spectrum for a single, unresolved star is subtracted from the two dimensional power spectra for binary stars. Residuals to published orbits have been compared to magnitude differences and angular separations in order to search for systematic dependences on these parameters. It is generally concluded that the published error estimates for the author’s speckle observations are realistic estimates of their accuracies.