Optical monitoring of BL Lac object S5 0716+714 and FSRQ 3C273 from 2000
  to 2014
  Using the 1.56m telescope at the Shanghai Observatory (ShAO), China, we
monitored two sources, BL Lac object S5 0716+714 and Flat Spectrum Radio Quasar
(FSRQ) 3C 273. For S5 0716+714, we report 4969 sets of CCD (Charge-coupled
Device) photometrical optical observations (1369 for V band, 1861 for R band
and 1739 for I band) in the monitoring time from Dec.4, 2000 to Apr.5, 2014.
For 3C 273, we report 460 observations (138 for V band, 146 for R band and 176
for I band) in the monitoring time from Mar. 28, 2006 to Apr. 9, 2014. The
observations provide us with a large amount of data to analyze the short-term
and long-term optical variabilities. Based on the variable timescales, we can
estimate the central black hole mass and the Doppler factor. An abundance of
multi-band observations can help us to analyze the relations between the
brightness and spectrum. We use Gaussian fitting to analyze the intra-day light
curves and obtain the intra-day variability (IDV) timescales. We use the
discrete correlation function (DCF) method and Jurkevich method to analyze the
quasi-periodic variability. Based on the VRI observations, we use the linear
fitting to analyze the relations between brightness and spectrum. The two
sources both show IDV properties for S5 0716+714. The timescales are in the
range from 17.3 minutes to 4.82 hours; for 3C273, the timescale is 35.6
minutes. Based on the periodic analysis methods, we find the periods P(V) =
24.24 days, P(R)=24.12 days, P(I)=24.82 days for S5 0716+714, and P = 12.99,
21.76 yr for 3C273. The two sources displayed the "bluer-when-brighter"
spectral evolution properties. S5 0716+714 and 3C 273 are frequently studied
objects. The violent optical variability and IDV may come from the jet.
Gaussian fitting can be used to analyze IDVs. The relations between brightness
(flux density) and spectrum are strongly influenced by the frequency.
