The blazar AO 0235+164: is the new flare started yet?
ATel #16190; V. V. Vlasyuk, O. I. Spiridonova, E. V. Emelianov, T. A. Fatkhullin, A. S. Moskvitin, O. A. Maslennikova (Special Astrophysical Observatory of the Rus. Ac. Sci.)
on 14 Aug 2023; 18:44 UT
Credential Certification: Alexander Moskvitin (mosk@sao.ru)
Subjects: Optical, Blazar
Our team continues the regular observing of the blazars sample in search of possible correlation between its optical and radio activity events using by 1-meter Zeiss-1000 and 0.5-meter RC-500 reflectors, equipped with BVRI CCD photometers.
Our data for the blazar AO0235+164, taken with these telescopes in 2023 January-February, showed that it's brightness had been varied about R ~ 19.0 magnitude and demonstrated slow increasing from R = 19.05 (MJD = 59961.7) to R=18.50 (MJD = 59986.7). After period of blazar's invisibility in March-July we inspected it's brightness at August. Our data taken with RC-500 telescope revealed that the blazar AO0235+164 continued its brightening from R = 17.38mag (MJD = 60162.025) to 17.25mag (MJD = 60167.015) and to 17.15mag (MJD = 60170.044) during the last few nights.
So within period between February and August the blazar increased its brightness by 1.9 magnitudes and possibly will continue increasing phase. The photometric accuracy of our estimates was between 0.02-0.05 magnitudes for individual frames because of the bright Moon skies for earlier epochs.
All photometrical data were calibrated by us using by reference stars from Smith et al.(1985, AJ90,1184) and Gonzalez-Perez et al. (2001, AJ122,2055). Our last estimates of blazar brightness from RC-500 telescope were performed using by Andor iXon Ultra EM-CCD DU-897 camera with 512x512 pixels E2V chip.
More accurate reduction is necessary. We strongly encourage further multi-wavelength observations.
