The long-term color variability of the BL Lac object OQ 530.

The optical light curve of the BL Lac object OQ 530 is constructed based on published data. Diagrams showing the correlations of fluxes in different wavelength ranges are constructed and used to analyze the color variations. The relative spectral energy distribution of the variable source in the optical can be represented by a power law that is stable on long time scales. The average spectral index is −1.15±0.02, indicating that the radiation of the variable source probably has a synchrotron nature. [ABSTRACT FROM AUTHOR]