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Special Notice #223: BL Lac object 3C 454.3 undergoing bright flare

November 18, 2010: As was noted by AAVSO observer E. Erdelyi (Carlsbad, CA, USA) in a post to cvnet-discussion, the BL Lac object 3C 454.3 (AUID 000-BDC-612) appears to be undergoing a bright flare; the object was recorded by Erdelyi at V=13.659(0.013) on 2010 November 10.2708 (JD 2455510.7708). The last flare of comparable brightness was observed in 2007, when the object reached V ~ 13.4 around JD 2454335 (late August 2007). Photometry of this interesting event is encouraged.  Gamma-ray flaring and bright millimeter-wavelength radio emission from this source were both detected on 2010 November 17 by AGILE (Striani et al., ATel #3034) and SMA (Gurwell & Wehrle., ATel #3036).

We note that quasar and BL Lac data are not currently available through VSX, but observers may still submit data and plot finder charts for this object using the name "3C 454.3".  Please clearly identify the stars you use for comparisons as well as giving the assumed catalog magnitudes.

The blazar 3C 454.3 is located at the following (J2000) coordinates:

        RA: 22 53 57.75 , Dec: +16 08 53.6

Finder charts for this object may be plotted using VSP:

Please promptly submit all observations to the AAVSO using the name "3C 454.3".

This AAVSO Special Notice was prepared by M. Templeton.


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