Comparison of the observed and theoretical SEDs for KIC 9832227. Dots denote observed values, with 3σ vertical error bars, and equivalent waveband widths (horizontal bars). The inset shows the various theoretical SEDs: F1 – primary only, F2 – secondary only, F1+F2 – binary only, F1+F2+F3 – binary with a hypothetical third component (K/M dwarf or white dwarf; black lines, which differ only in the UV). Lower panel: residual in respect of the three-component solution: blue dots – white dwarf, yellow dots – K/M dwarf for the third component. The stellar atmosphere models of Castelli et al. (1997) and Koester (2010) are used (see text and Appendix C for more details).