Very high optical polarization of PKS 1725+123
ATel #17393; Rumen Bachev, IA-NAO, BAS
on 17 Sep 2025; 16:37 UT
Credential Certification: Rumen Bachev (bachevr@astro.bas.bg)
Subjects: Optical, AGN, Blazar, Quasar
Following reports of enhanced activity of the FSRQ blazar PKS 1725+123 in VHE (ATel #17344), gamma-rays (ATel #17316, ATel #17370), optical (ATel #17345) and radio wavelengths (ATel #17356), we started observing this object with the 60-cm Belogradchik telescope, Bulgaria. The blazar showed persistent, but very high optical (R-band) polarization, among the highest we have ever measured in a blazar. The results from the nights Sept. 15th and 16th are preliminary and are listed below.
| JD |
R-mag (err) |
P (err) [%] |
EVPA (err) [deg] |
| 2460934.26 |
14.43 (0.05) |
35.2 (0.8) |
11.8 (0.5) |
| 2460935.24 |
14.47 (0.05) |
36.2 (0.5) |
10.6 (0.7) |
Further observations are encouraged. This research was partially supported by the Bulgarian National Science Fund of the Ministry of Education and Science under grants KP-06-H68/4 (2022), KP-06-H78/5 (2023), and KP-06-H88/4 (2024).
