Multi-frequency Observation and Theoretical Study for Blazar Objects

Based on the collections of a huge amount of observations, fundamental observational characteristics of Blazars are summarized comprehensively and some observational properties are interpreted in terms of different mechanisms.Complete sample of BLLac is given in this paper.The relevant theories of Blazar objects have been introduced which including the correlations between different wavelength light curve periodic analysis, Hubble diagram, and active variabilities in polarization and polarization angle.The observations wedid with CCD photometry and spectrum for 3C345, have been introduced.Historical light curves of 3C345 and its periodic analysis are also analyzed.It is shown that there is a period of(10±0.8)a for 3C345, and there is a massive black hole with M =10^{6M⊙in its center.}