The Medium and Long Period Light Variation Characteristics of FSRQ 3C 454.3

Blazars have obvious and intense large-scale light variations. The study of light variations on medium and long time scales plays an important role in revealing the characteristics and mechanism of light variations of Blazars. By selecting the original optical B, V, R and infrared J, K bands of the flat-spectrum radio quasar 3C 454.3 from June 2008 to July 2017, the medium and long period characteristics of 3C 454.3 are studied by power spectrum method. It is concluded that the main period of light variation is 1.25 years, and the period of 4.57 years is the superposition of 1.25 years. 3C 454.3 is related to the optical, infrared and radio variations. The results show that the infrared luminosity of 3C 454.3 is brighter than that of optical band, and the infrared light variation is more intense than that of optical band.