The impact of bright extended sources on the observation and detection of faint sourcesby Gaia has been studied. The effect has been characterized using the representative caseof stars near the Jupiter disk and consists of three parts. First, an analyticalrepresentation of the PSF, including aberrations and electronic distortions, has beendeveloped to produce images of Jupiter and solar type stars. Second, those images havebeen combined to produce fields of view including Jupiter and stellar patterns. Third, theCCD images have been fed to the VPU algorithms prototype to determine the limits untilwhich detections are possible. This work can be useful for science cases such as GAREQ.