Rapid optical variability of S4 0954+65
ATel #14452; Rumen Bachev (IA-NAO, BAS, Bulgaria)
on 10 Mar 2021; 14:56 UT
Credential Certification: Rumen Bachev (bachevr@astro.bas.bg)
Subjects: Optical, Blazar
After the reports of gamma-ray activity of S4 0954+65 (ATel #14426), the blazar was observed during the nights of March 7th and 8th, 2021, with the 0.6m telescope of Belogradchik Observatory, Bulgaria. We monitored the object for 4 - 5 hours each night in 3 optical bands (VRI). S4 0954+65 showed significant intra-night variations of 0.2 - 0.3 mag each night, with gradients of up to 0.2 mag for an hour. The average R-band magnitudes were 14.78 (March 7.88 - 8.03 UT) and 14.65 (March 8.86 - 9.06 UT), meaning the object was still brightening (ATel #14444). In addition, moderately strong linear polarization was detected, p = 7 +/- 1 %, PA = 170 +/- 5 deg. (unfiltered light, March 8.99). All results are preliminary, yet indicative for a strong optical activity of the blazar. Further monitoring is recommended.
Belogradchik Observatory is operated by the Institute of Astronomy and NAO, Bulgarian Academy of Sciences. This study was partially supported by the Bulgarian Science Fund through grands KP-06-H28/3 (2018), KP06-PN38/4 (2019) and KP-06-KITAJ/2 (2020).
