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We present UBVRI photometry for SN 1993J, as well as data on its likely progenitor. The post-explosion data were obtained with CCDs attached to telescopes (0.4 to 0.6m) on the campuses of the Keck Northeast Astronomy Consortium (KNAC) and on the Burrell Schmidt telescope of the Warner and Swasey Observatory, Case Western Reserve University, at KPNO by the authors and their undergraduate students. We have obtained a fairly well-sampled light curve of the early stages in the outburst, including the rapid decay (0.30 magnitude per day at V) from the initial maximum and the subsequent slower rise to the secondary maximum.
The position of the supernova, as measured on our images agrees to within 0.1 arc-sec with the position of a faint, apparently stellar image, taken with the 0.9m telescope at KPNO on 1992 October 2. The brightness of this object (Perelmuter, IAUC 5736; Filippenko, IAUC 5737; Humphreys {\sl et al.}, IAUC 5739) are consistent with its being a late-type supergiant. A series of images of M81 taken in 1992 November and 1993 February are analyzed to provide further constraints on the likely progenitor and its photometric behavior in the months before its explosion.
We acknowledge the generous support of the W. M. Keck Foundation for providing the CCD cameras and workstations and for their support of astronomy at the KNAC institutions.
