Exceptional optical flare of the radio galaxy NGC 1275

ATel #18062; Alessandro Marchini (Astronomical Observatory, DSFTA, University of Siena - Italy); Leonardo Stiaccini, Gaia Verna (Department of Physical Sciences, Earth and Environment (DSFTA), University of Siena - Italy); Giacomo Bonnoli (INAF - Brera Astronomical Observatory, Milan - Italy).
on 20 Sep 2026; 14:07 UT
Credential Certification: Gaia Verna (gaia.verna@unisi.it)

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Last night the radiogalaxy NGC 1275 (a.k.a. 3C 84, S4 0316+41) at R.A. 49.95 deg, Dec. +41.51 deg (J2000.0) and z=0.0176 (Strauss et al., 1992, Astrophysical Journal Supplement v.83, p.29) reached an extreme optical magnitude of 12.629 ± 0.003 in the R band and 13.137 ± 0.004 in the V band of the Johnson-Cousins photometric system. Quoted uncertainties are statistical only.

The source was already observed in an exceptionally bright optical state on 10 Aug 2026 (ATel #17955), and it has been recently detected at very-high-energy (VHE; E>100 GeV) by MAGIC and LST-1 (ATel #18060).

Observations were conducted from the 0.30 m telescope of the Astronomical Observatory of the University of Siena (Siena, Italy - IAU MPC observatory code K54)

Any inquiry on these observations can be addressed either to Alessandro Marchini (marchini@unisi.it) or to Gaia Verna (gaia.verna@unisi.it). We will continue monitoring the source in the following nights. Multi-wavelength follow-up is strongly encouraged.

Brief descriptions of the instrumental setups used for the reported observations are available at the official webpage of the Astronomical Observatory of the University of Siena.