BVRI CCD-PHOTOMETRY OF COMPARISON STARS IN THE FIELDS OF GALAXIES WITH ACTIVE NUCLEI. VII

摘要

Data are presented from observations in the B, V, R, and I bands of 234 comparison stars in the fields of 21 active galactic nuclei (AGN) with right ascensions from 9 to 24 hours over a wide range of stellar magnitudes. Most of the AGN are blazars and quasars. The B, V, R, and I magnitudes of the overwhelming majority of these stars were not known previously. Finding charts for these stars are provided. These observations can be used for differential photometry of galactic nuclei.