zero flux). We held $u1$ fixed as before but now also put Gaussian priors on $u2$ with means equal to the values from [@Claret2011] and standard deviations from the propagated errors in the effective temperature and surface gravity of the host star. This prior was necessary as the limb darkening and spot models can play off each other in trying to fit the transit shape.

The MCMC was initiated with the system parameters equal to those in [@Hebrard2013] and was run for 10000 steps in burn in and another 10000 steps in the production run. There were 31 fitted parameters with 124 walkers. The parameters governing a spot’s characteristics are correlated with one another. The correlation between spot contrast and size has been shown previously by e.g. [@Pont2007], [@Wolter2009], [@Reed2013] and [@Beky2014]. We initiated the MCMC starting positions with spots at various, randomly selected, latitudes on the stellar surface so as not to bias the fits and test for convergence. After the burn in phase the error bars in the data points were rescaled to give a reduced $\chi^2$ of unity.

After the first MCMC chain, a second MCMC was run but this time with the parameters that were tied 