The repeating flares of the blazar S4 0954+65 in 2023 March-May
ATel #16030; V. V. Vlasyuk, O. I. Spiridonova, A. S. Moskvitin, O. A. Maslennikova (Special Astrophysical Observatory of the Rus. Ac. Sci.)
on 6 May 2023; 05:51 UT
Credential Certification: Alexander Moskvitin (mosk@sao.ru)
Subjects: Optical, Blazar
Referred to by ATel #: 16041
Blazar S4 0954+65 is observing by SAO RAS team as a very promising object demonstrating unusual behavior on different timescales. We had used SAO RAS 1-meter and 0.5-meter optical
telescopes equipped my CCD photometers within course of our studies as was described in our earlier telegrams (ATels#15344, #15376, #15633).
As it was noted by us earlier (ATel#15861), S4 0954+65 had begun current year in a very low state, reaching R magnitude as low as 17.0. Brightness between 16th and 17th magnitudes was
typical for it till end of February.
Current phase of activity started since March,2 with increasing of blazar R-magnitude above 15.6. The first flare of S4 0954+656 in current year was noted in ATel#15960, when it's R-magnitude reached 13.5.
Our following inspection of its brightness revealed at least 4 powerful flares between last decade of March and first days of May. Below we present epochs of local R-magnitudes maxima and corresponding values according to our data.
MJD, days R-magnitude
60029,74 13.44
60049,85 13.55
60061,87 13.88
60069,04 13.48
Evidently, that time interval between individual flares decreased from 20 to 7 days for the last flare with it's very similar brightness.
Some signs of intraday variability were found by us and should be analyzed more accurately. Data taken at consecutive nights showed fast variation of flux --- about 1 magnitude per day and even more.
The most of data were taken under good weather condition (seeing about 2 arcsec) and have typical accuracy about 0.01 mag. More accurate reduction and deeper analysis of our collected data is necessary. We strongly encourage further multi-wavelength coverage.
