OM Photometric Calibration using Abell 2690

CALThe primary goal of the observation Abell 2690 is to accomplish andaid the photometric calibration of OM in the B and V filter. This comprises the definition of the zero point magnitude of the natural system and the calculation of the coefficients of the colour transformation. Secondary calibration item is the measurement of theinstrument PSF, which is accomplished by placing fast mode windows on two field stars. The change of count rate with window size is the purpose ofintroducing exposures with small image mode windows in the Vfilter and the magnifier. The change of PSF with window size can be best studied with magnifier exposures. estimated OM overhead 7.4ksec. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]