Spurious 'active longitudes' in parametric models of heavily spotted eclipsing binaries

Abstract

In this paper, the size distributions of starspots extrapolated from the case of the Sun are modelled on the eclipsing binary SV Cam to synthesize images of stellar photospheres with high spot filling factors. These spot distributions pepper the primary's surface with spots, many of which are below the resolution capabilities of eclipse-mapping and Doppler-imaging techniques. The light curves resulting from these modelled distributions are used to determine the limitations of image reconstruction from photometric data. Surface brightness distributions reconstructed from these light curves show distinctive spots on the primary star at its quadrature points. It is concluded that two-spot modelling or chi-squared minimization techniques are more susceptible to spurious structures being generated by systematic errors, arising from incorrect assumptions about photospheric surface brightness, than simple Fourier analysis of the light curves. © 2005 RAS.