Indico will be down for maintenance starting at 5PM CST on Dec 12th 2023. Most Indico features will be available starting at 6:30CST. Registration for events involving Site Access and Badging will not be available until 9PM CST.
I will describe the ESA's Gaia astrometric mission and its scientific potential, briefly reporting on the science performances. Then I will focus on the flux calibration model and on the ongoing ground-based campaign started to build the Gaia spectrophotometric standard stars grid, which requires approximately 200 stars, calibrated to a few percent with respect to Vega, and covering different spectral types.