Slow but steady increase of brightness of NGC 1275 over the last 5 months
ATel #15938; L. Kimmel, O. Domann, B. Mengelkamp, D. Scheuermayer, M. Heidemann, R. Goldbach, F. Wehr. T. Apell, E. Ankara, N. Bader, L. Bertsch, N. Boutter, M. Daig, K. Heidemann, F. Hemrich, B. Horst, F. Kaplan, F. Kees, D. Kuberek, J. Ludwig, K. Rosenlehner, K. Schoch, J. Seufert, L. Waller, R. Steineke, D. Reinhart, N. Zottmann, M. Feige, C. Lorey (all Friedrich-Koenig-Gymnasium / Hans-Haffner-Sternwarte, Wuerzburg, Germany) L. Kunkel, A. Scherbantin, L. Schneider, K. Mannheim, (all University of Wurzburg, Germany) D. Elsaesser (TU Dortmund, Germany)
on 9 Mar 2023; 10:50 UT
Credential Certification: Dominik Elsaesser (dominik.elsaesser@tu-dortmund.de)
We detected at the Hans Haffner Observatory a high state of brightness of the active galaxy NGC 1275 (3C 84; RA = 03 19 48.156, Dec = +41 30 42.109, ICRS=J2000; z = 0.0175 - cf. SIMBAD Astronomical Database).
While the brightness of this source fluctuated around 13.2 (R-Band) in the first two thirds of the year 2022, the brightness increased slowly but steadily since early September 2022 from about 13.1 mag until it stagnated in the last third of February 2023 at around 12.9 mag. From February 27th, a stronger increase in brightness could be measured to just below 12.8 on March 3rd.
It is noteworthy that this source showed strong gamma-ray activity End of December 2022 (20th - 22th December) and at Beginning of January 2023 (10th - 11th January) (ATel #15819, ATel #15820, ATel #15823, ATel #15856). IceCube also reported reaching an upper limit in the search for track-like muon neutrino events in this time frame (Atel #15852). Due to bad weather conditions, we only have one value from this period, from 17th December and then again from 27th of December, but we do not see a particularly high optical brightness there, only a continuous, slow increase.
The last time we measured an optical magnitude of NGC 1275 similar to the one we are reporting now was in April 2018 at 12.752 ± 0.003 mag (R-band).
We report the following preliminary R-band magnitudes:
from September 2022 to February 2023:
JD 2459834.5774: 13.162 ± 0.010
JD 2459839.5323: 13.129 ± 0.006
JD 2459858.4386: 13.105 ± 0.003
JD 2459871.2466: 13.085 ± 0.007
JD 2459883.3983: 13.085 ± 0.003
JD 2459895.3269: 13.048 ± 0.015
JD 2459906.5335: 13.038 ± 0.003
JD 2459926.4181: 13.010 ± 0.003
JD 2459931.3741: 12.987 ± 0.003
JD 2459941.3853: 12.926 ± 0.003
JD 2459945.5979: 12.921 ± 0.004
JD 2459965.2638: 12.904 ± 0.006
JD 2459984.5068: 12.857 ± 0.004
JD 2459996.5245: 12.862 ± 0.004
JD 2459997.5021: 12.864 ± 0.004
JD 2460002.4949: 12.854 ± 0.004
JD 2460003.4261: 12.867 ± 0.004
JD 2460004.4426: 12.827 ± 0.006
March 2023:
JD 2460005.4415: 12.840 ± 0.006
JD 2460006.4392: 12.807 ± 0.005
JD 2460006.5305: 12.796 ± 0.013
JD 2460007.3531: 12.797 ± 0.004
The measurements were made with the 0.5m CDK-astrograph using Bessel-Filters. Comparison stars were taken from Doroshenko et al. (2005, Astrophysics 48, 156). An aperture radius of 5 arcsec was used for photometry.
These 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 at the school and university observatory Hans-Haffner-Sternwarte in D-97265 Hettstadt (Germany).
AGN Monitoring Program at the Hans-Haffner-Sternwarte in Hettstadt
