Notes. The timing solution was obtained adopting the source coordinates from Chakrabarty et al. (2011). The term P_orb is the orbital period, a₁sin i is the projected semimajor axis, and T_asc is the epoch of passage at the ascending node. To take into account the large value of the reduced χ² obtained from the fit, we rescaled the uncertainties of the fit parameters by the square root of that value (see, e.g., Finger et al. 1999). Uncertainties are the 1σ statistical errors.