OQ 334 has reached a new maximum optical magnitude of brighter than 13 mag in the R-band

ATel #17873; S. Krauth, S. Ankara, L. Neisser, M. Grischy, J. Meiler, E. Bommert, S. Duerr, O. Domann, R. Goldbach, M. Heidemann, D. Kuberek, L. Lehmann, N. Mildner, F. Pfeuffer, K. Warmuth, M. Feige, M. Kopp, D. Reinhart, R. Steineke, N. Zottmann, C. Lorey (all Hans-Haffner-Sternwarte, Friedrich-Koenig-Gymnasium, Wuerzburg, Germany) J. Hessdoerfer, M. Kadler, L. Haury, K. Mannheim, F. Roesch (all University of Wurzburg, Germany) D. Elsaesser (TU Dortmund, Germany)
on 5 Jul 2026; 13:23 UT
Credential Certification: Dominik Elsaesser (dominik.elsaesser@tu-dortmund.de)

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The flat spectrum radio quasar OQ 334, also known as QSO B2 1420+326; ICRS coord. (ep=J2000): RA 14 22 30.38; Dec +32 23 10.44 (Optical); z=0.68144 (Data from SIMBAD (http://simbad.u-strasbg.fr/simbad/) reached an exceptionally high magnitude of 12.754 in the R-band last night.
The object has been in a very active state since early April (ATel #17745) and is showing extreme high states across wavelength ranges (ATel #17782, ATel #17790, ATel #17802, ATel #17821, ATel #17835, ATel #17854). The current phase of activity had already begun to become apparent as early as February 2026 (ATel #17654) or even as early as the end of November 2025 (ATel #17504) and has been growing in intensity ever since.
In mid-March, the optical brightness of the object increased by roughly a magnitude, so that from the end of March onwards it remained between 15.2 and 15.6 mag (R-band) for several weeks. From the beginning of May, the R-band brightness rose sharply by almost 2 magnitudes within 12 days. Since then, the brightness has remained between 13.7 and 13 mag. Over the last two nights, the optical magnitude then significantly exceeded 13 mag, reaching a peak of 12.754 last night at JD 2461226.46905.

We report the following preliminary R-band magnitudes:

JD 2461225.3721 12.912 ± 0.024
JD 2461225.4247 12.964 ± 0.016
JD 2461225.4801 12.892 ± 0.010
JD 2461225.5620 12.835 ± 0.015
JD 2461226.3602 12.794 ± 0.025
JD 2461226.4154 12.779 ± 0.006
JD 2461226.4691 12.754 ± 0.033


Our measurements are carried out as part of the long-term AGN monitoring program of the Naturwissenschaftliches Labor fuer Schueler am Friedrich-Koenig-Gymnasium (FKG), the Universitaet Wuerzburg, and TU Dortmund University.
Comparison stars and their magnitudes were taken from the APASS DR9 catalogue (Henden et al., 2016). The Sloan magnitudes were transformed to the Johnson-Cousins system with the equations by Lupton (2005).
The optical data were acquired through a Bessel R filter (Chroma) with a 0.5m CDK-astrograph (PlaneWave) and a Moravian C4-16000EC camera at the school and university observatory Hans-Haffner-Sternwarte in 97265 Hettstadt, Germany (https://schuelerlabor-wuerzburg.de/en/observatory/).

Hans-Haffner-Sternwarte