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We show that the candidate progenitor of the core-collapse SN 2011dh in M51(8 Mpc away) was fading by 0.039 +- 0.006 mag/year during the three years priorto the supernova, and that this level of variability is moderately unusual forother similar stars in M 51. While there are uncertainties about whether thetrue progenitor was a blue companion to this candidate, the result illustratesthat there are no technical challenges to obtaining fairly high precision lightcurves of supernova progenitors using ground based observations of nearby (<10Mpc) galaxies with wide field cameras on 8m-class telescopes. While othersources of variability may dominate, it is even possible to reach into therange of evolution rates required by the quasi-static evolution of the stellarenvelope. For M 81, where we have many more epochs and a slightly longer timebaseline, our formal 3 sigma sensitivity to slow changes is presently 3millimag/year for a M_V ~= -8 mag star. In short, there is no observationalbarrier to determining whether the variability properties of stars in theirlast phases of evolution (post Carbon ignition) are different from earlierphases.

Discovery of Variability of the Progenitor of SN 2011dh in M51 Using the Large Binocular Telescope