the star.

For the photon shot noise, we used the latest estimates of the expected precision of the Kepler observations at different $m_v$. These data were provided to HK by the Kepler team.

### Generation of the artificial data {#sec:gen}

Components due to granulation and active regions were generated in the time domain using a stochastic, autoregressive model of the AR\[1\] type (e.g., see Koen 2005).

We used code based on the latest version of the solarFLAG (Chaplin et al. 2006) timeseries generation code to make the p-mode timeseries (the solarFLAG generator is described in Chaplin et al., in preparation). Each ($n,l,m$) component was generated in the time domain. Components were modeled as forced, damped harmonic oscillators, re-excited at frequent intervals (here, every minute). The oscillators were re-excited by a timeseries of ‘kicks’ made from the granulation noise. Kicks given to overtones of the same ($l,m$) were correlated. Implicit in this approach is the assumption that on the Sun, the excitation function of a mode of a given ($l,m$) is the same as the component of the granulation that has the same spherical harmonic projection over the corresponding range in frequency (Toutain, Elsworth & Chaplin 2005). Correlations of the excitation 