The scientific capabilities of the Evanescent Wave Coronagraph EvWaCo

Abstract The Evanescent Wave Coronagraph, EvWaCo, is an in-development prototype coronagraph, designed for use on the 2.4m Thai National Telescope (TNT), in R and I-band filters. This work examines astronomical capabilities of EvWaCo using results from Fourier-analysis simulations. Fourier optics simulations were applied to analyse its performance, combining different sources contrast degradation that will be present system. used main analysis assume a good night at Observatory (TNO) include fitting error, aliasing, measurement noise lag, providing radially averaged curve. From curve, detection limit, as defined by minimum signal ratio 5 typical observation time, can calculated primary star magnitudes. relative fluxes various binary stars, with range spectral classes separations, modelled allowing comparison curves. photon-noise limited curves provide theoretical baseline performance achieved EvWaCo; they, therefore, give indication types objects observe. Along broader discussion observable objects, number known systems are suggested observations TNT EvWaCo.