Alert Notice 808: Bright outburst of the blazar 4C 31.03

January 9, 2023

AAVSO Forum threads (scroll to the bottom of a thread for latest posts):
- High Energy Network (HEN):
- Time Sensitive Alerts:

Please subscribe to these threads if you are observing 4C 31.03 so you can be updated. Join in the discussion or ask questions there!

The blazar 4C 31.03 is undergoing an unprecedentedly bright outburst.

Ciprini et al. (ATel #15841) report that gamma-ray flaring in this Active Galactic Nucleus (AGN) was detected by the Fermi Large Area Telescope (LAT) om 2023 January 1 and 2.

Follow-up optical observations by Seiichiro Kiyota (Kamagaya, Japan, using a 0.25-m SCT + QSI 632ws CCD; via vsnet-alert 27294) show the quasar brighter than ever previously detected: 2023 Jan.  4.4057 12.45 V; 4.4061 12.12 Rc; 4.4066 UT 11.70 Ic. His images of the object in quiescence and outburst may be seen at:

Sebastián Otero (AAVSO) provides the compiled historical light curve below that demonstrates the unusual nature of the current outburst. This light curve is also available via the VSX page for 4C 31.03.


AAVSO High Energy Network (HEN) Section Leader David Hinzel has posted to the AAVSO HEN forum; that forum thread is given in the above Forum links. He recommends follow-up observations in all filters (UBVRI) beginning immediately and continuing until the quasar has returned to its normal behavior. DSLR observations are also welcome. The usual range of 4C 31.03 is V magnitude 15-19.

Coordinates (2000.0):  R.A. 01 12 50.33  Dec. +32 08 17.4      (Psc)   (from VSX page for 4C 31.03)

Charts with comparison stars for 4C 31.03 may be created using the AAVSO Variable Star Plotter (VSP). The AAVSO Sequence Team is currently preparing this sequence. If it is not available when you create a chart, please try again a little later.

Please submit observations to the AAVSO International Database using the name 4C 31.03.

This AAVSO Alert Notice was compiled by Elizabeth O. Waagen using information provided by Sebastián Otero and David Hinzel.


Information on submitting observations to the AAVSO may be found at:
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 - Spectroscopy:


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