Variable Stars in M13. I. Positions and UBVRI Photometry for Variables, Suspected Variables, and Comparison Stars

摘要

Photoelectric and photographic UBVRI photometry is presented for 104 of the brighter stars in the field of the globular cluster M13 (NGC 6205). The observed objects include the known variable stars of the cluster, suspected variables, and a number of field stars suitable for calibrating CCD and photographic images and for serving as comparison stars for studies of the variables. Accurate relative J2000.0 positions for the stars are also given.