GALEX meta-data

Schiminovich and I spent a good part of the day trying to understand brightness variations in GALEX sources, taken not from the official catalogs (which are great) but rather from our own analyses of some intermediate data products ("movies" of the photon arrival data). We are looking for time variations that are real, but we are being fooled by some meta-data problems, in which exposure times are not what we think they are. It was a frustrating day, but we did find what appears to be the problem. It is not clear that we can fix it adequately, so we might have to take the Astrometry.net-endorsed route of reconstructing the meta-data from the data through consistency or internal calibration.

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