The results of both BVRI CCD photometric monitoring and fast photometry in a certain optical waveband for 4 blazar objects and variable quasar are presented. The results show that 1) 3C 120 has a short time scale variability about 20 min, with the different shape of light curve and with different amplitude (one is 0.21+/-0.06 mag, the other is 0.053+/-0.014 mag) in different night. One day timescale variability was also observed, with a maximum decrease of the flux near 20%. 2) OJ 287 has a variability on a timescale of one day, with the maximum amplitude of changes about 0.2 mag. Since 1990, the source brightened near 0.8 mag. 3) 3C 345 is fainter during observing periods, the faintest magnitude B similar to 17.5 mag it seems variable from night to night. 4) The variability with a small amplitude about 0.1 mag appear on a timescale of about 10 months in the data of PHL 658. The values of the colour index of the blazars in each night are given.
修改评论