Testing the energy scale of the CELESTE experiment

The uncertainties on the absolute energy scale of the CELESTE experiment affect the constraints CELESTE can impose on > 30 GeV gamma-ray emission models. To date, these uncertainties have been of order 30 %. The optical throughputs of the atmosphere and the detector are key to understanding the energy scale. We are comparing CELESTE photomultiplier anode currents measured for bright stars with predictions from the detector simulation. In these studies we include data from recently installed radiometers, and from the LIDAR operating on the site.