Direct starlight component of the LISRF spectrum. Upper panel: Total spectrum, the spectrum of Gaia AP stars, the recovered spectrum of Gaia non-AP stars, and the spectrum of the HIPPARCOS stars not included in the Gaia catalog. For the total spectrum (and for the Gaia AP com-ponent) I also plot the synthetic J_λ values in the Gaia bands together with the esti-mates from the direct flux summation. I also show observational UV and NIR estimates and the corresponding synthetic photome-try (for the full spectrum only). The relative difference between observations and syn-thetic photometry is shown in the bottom panel. The shaded area refers to the esti-mated uncertainty for the total spectrum (see text for details).