The blazar S4 0133+47: the brightest flare since 2023 September and still growing up
ATel #16986; V. V. Vlasyuk, O. I. Spiridonova (Special Astrophysical Observatory of the Rus. Ac. Sci.)
on 21 Jan 2025; 11:23 UT
Credential Certification: Alexander Moskvitin (mosk@sao.ru)
Subjects: Optical, Blazar
We continue regular observing of the blazars sample in search of possible optical activity events using 1-meter Zeiss and 0.5-meter RC-500 reflectors, equipped with BVRI CCD photometers.
The FSRQ S4 0133+47 (aka DA55 or J0136+4751) at z = 0.859 is a member of our bright blazars sample. Its last outburst was detected by our team in 2023 July. We reported its maximal flux density in Rc-band as 15.38 +/- 0.02 mag (ATel #16146). Few weeks later we noted a fast 1-magnitude flare, when its flux achieved a higher level of R = 15.00 +/- 0.02 (MJD 60188, 2023, Sep.31) from 16th mag level within +/- 2 days interval.
Our following studies showed that its brightness varied between R = 17.0 mag and 18.5 mag till September of 2024 with two exceptions --- in December of 2023 (short flash with R about 16.4 mag) and June of 2024 (flare with R about 16.6 mag).
New brightening epoch for S4 0133+47 started last November, then its flux density exceeded a level of R = 18.0 mag and began slow but stable growing up to a level of R = 16.1 mag (MJD 60695.7, January 20/21). The mean slope of flux increase is about 0.01 mag per day, but the brightening process became faster by a factor of (5-7) within the last few days.
All photometrical data were calibrated as it was noted earlier (see ATel #15626). More accurate reduction is necessary. We strongly encourage further multi-wavelength observations.