BVRI photometry of B2 1420+326
ATel #17897; E. Zaharieva, B. Aleksandrov, V. Efremov, M. Petrova, A. Todorov, E. Ovcharov (Sofia University, Bulgaria)
on 15 Jul 2026; 22:44 UT
Credential Certification: Evgeni Ovcharov (evgeni@phys.uni-sofia.bg)
Subjects: Optical, Blazar
Following the recent reports of an exceptionally high optical state of the changing-look blazar B2 1420+326 (OQ 334, z=0.68) - ATel #17884, #17873, #17874 and references therein - we performed BVRI photometric monitoring of this object with the 35 cm Schmidt Cassegrain telescope + CCD SBIG STX-16803 in BVRI bands at the student Space and Earth Sciences Summer School "Prof. Marin Bachevarov", Dren, Bulgaria, during the nights of July 13/14 and 14/15, 2026. The preliminary nightly magnitudes are listed below:
JD Filter mag ± err
2461236.3364 B 13.472 ± 0.063
2461236.3387 B 13.523 ± 0.030
2461236.3409 B 13.574 ± 0.033
2461236.3432 B 13.612 ± 0.0243
2461236.3454 B 13.616 ± 0.072
2461235.4186 I 12.375 ± 0.06
2461235.4208 I 12.390 ± 0.17
2461235.4231 I 12.437 ± 0.261
2461235.4253 I 12.535 ± 0.155
2461236.3703 I 12.382 ± 0.018
2461236.3726 I 12.39 ± 0.023
2461236.3748 I 12.376 ± 0.023
2461236.3771 I 12.378 ± 0.026
2461236.3793 I 12.384 ± 0.030
2461235.3868 R 12.795 ± 0.021
2461235.3891 R 12.789 ± 0.019
2461235.3913 R 12.784 ± 0.013
2461235.4050 R 12.785 ± 0.012
2461235.4073 R 12.797 ± 0.021
2461235.4095 R 12.775 ± 0.018
2461235.4118 R 12.789 ± 0.014
2461235.4141 R 12.783 ± 0.015
2461236.3590 R 12.824 ± 0.013
2461236.3613 R 12.825 ± 0.013
2461236.3635 R 12.829 ± 0.016
2461236.3658 R 12.827 ± 0.013
2461236.3680 R 12.832 ± 0.015
2461236.4105 R 12.840 ± 0.016
2461236.4127 R 12.859 ± 0.019
2461236.4150 R 12.886 ± 0.055
2461235.3938 V 12.995 ± 0.02
2461235.3960 V 13.008 ± 0.017
2461235.3983 V 12.979 ± 0.027
2461235.4005 V 13.011 ± 0.03
2461236.3477 V 13.058 ± 0.020
2461236.3500 V 13.044 ± 0.025
2461236.3522 V 13.035 ± 0.018
2461236.3545 V 13.043 ± 0.020
2461236.3567 V 13.043 ± 0.021
Compared to the R-band magnitudes reported in ATel #17884 (R = 12.42 on July 9th), our measurements indicate that the source has faded by about 0.4 mag and continues a gradual decline from its historical optical maximum, while still remaining in an exceptionally bright state. Comparison stars and their magnitudes were taken from the APASS DR9 catalogue (Henden et al., 2016).
The study was supported by the National Program 'Education with Science' D01-172/18.09.2024 and the National RI Roadmap Project D01-109/30.06.2025 with the Ministry of Education and Science of the Republic of Bulgaria.
