<i>BVR</i> photometry of comparison stars in selected blazar fields

Abstract

We present photometric sequences in the Johnson's BV and Cousins' R bands in the fields of 10 BL Lacertae objects (BL Lacs) monitored at the Torino Astronomical Observatory. Data were taken during 14 photometric nights from February 1995 to May 1997. The 56 calibrated stars are brighter than and can be used as comparison objects in order to derive the BL Lac magnitudes. Finding charts are included for the stars identification.