Abstract
Abstract In this work, we present the results of the recent quasi-simultaneous multi-band optical observations (in BVRI) of the blazar BL Lacertae over diverse timescales. For this study, the source was observed from September 2020 to October 2020 using six different telescopes around the world, collecting ∼5800 photometric image frames in BVRI. The source displays many episodes of significant intraday variability, and the amplitude increases with the brightness of the target. Moreover, the object also showed significant variability on a short-term basis, with amplitude of flux variabilities as 85.6 %, 78.9 %, 93.4 %, and 67.6 % in B, V, R, and I passbands, respectively. The color-magnitude analysis of the source displays dominantly bluer-when-brighter behavior on both intraday and short timescales, which can be attributed to the energetic processes in the jet. Correlation analysis points towards a strong correlation between optical bands with no firmly detectable time lags. Moreover, we also performed the periodicity search using the Lomb-Scargle and Weighted Wavelet Z-transform methods and found plausible indications of the presence of quasi-periodicity in the blazar. We also generated spectral energy distributions for nights with quasi-simultaneous observations in all four bands and found the spectral index to range from 2.9 to 3.2, which can be ascribed to a strong jet contribution. We discuss the results within the framework of prospective source intrinsic and extrinsic scenarios.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call