These are derived in the I, J, H, and K bands from tabulated values [@Claret2000] using the stellar mass, temperature and metallicity found by @Burke2007, and interpolated at the mean of the NICMOS band, 1.54 $\mu$m. We find $u_1=0.054$ and $u_2=0.417$.

The minimization process includes a decorrelation from instrumental parameters. The instrumental model includes a second order polynomial in the angle $\alpha$, and a linear combination of $x$, $y$, the FWHM $w$, and the detector temperature $T$. The 3 visits are treated separately. In addition, the filter wheel is displaced after HST re-enters the Earth shadow leading to 2 distinct positions (see Figure \[fig:state parameters\]). Thus, we divide the data into 6 groups, with 2 groups per visit. A multiplicative constant $F_0$ is used to adjust the flux level between each group. The instrumental model $\Psi$ is computed independently for each group $g$, whereas the transit model $\Phi$ remains the same. The model lightcurve thus can be written as: $$F_{mod} \; = \;  \Phi(R_\star,r,\tau_{14},t_1,t_2,t_3,a_1,a_2)  \;\times\big\{F_{0}\times\Psi(\alpha^2,\alpha,x,y,w,T)\big\}_{g \,\in\,\llbracket 1,6 \rrbracket}
\label{eq:mcmc photometry}$$

The first orbit of each visit is strongly affected by HST settling; those data are discarded. The time for each observation is the midpoint of the exposure converted to barycentric 