the distribution[^5]. At larger distances, we take $\rho_* \approx 0$. The adopted value of the central stellar density $\rho_0$ implies the same mass as $1.7$ cm$^{-3}$ of pure Hydrogen, or $\sim1.2$ cm$^{-3}$ in the case of the ISM, where Hydrogen accounts for $\sim72$ per cent of the gas mass. The contribution of stars to the local density near the Sun is thus comparable to that of the gaseous component. The cumulative surface density $$\Sigma_*(z) = 2\rho_0\ \left[ z - 0.9 \left( \frac{z^2}{h_*} - \frac{z^3}{3h_*^2} \right) \right]
\label{eqSigmaStar}$$ increases up to $\sim 17.5$ M$_\odot$ pc$^{-2}$ at $z=h_*$, about 3 times the observed surface density of Hydrogen (in all forms) at the solar radius, and 2 times that of the ISM gas, adding up the mass in Helium and heavier elements.

When the contribution of the stellar component to the gravitational acceleration is taken into account, the pressure gradient required to maintain hydrostatic equilibrium increases, and the transition between the cold and the hot phase moves inwards by about a factor of 2 (top panel in Figure \[figRhoStar\_B\]). In general terms, the presence of an external gravitational potential will always push the gas distribution inwards, leading to a reduction of the relevant 