3C 273 - half a century later
  We have presented an optical monitoring of 3C 273, the first quasar discovered fifty years ago. It does not show variability both on intra-night and long-term time scales. To facilitate the further monitoring of 3C 273, we compiled the available calibrations of the comparison stars in its field into a mean sequence. 
L. Slavcheva-Mihova, B. Mihov, I. Iliev
astro-ph.HE