Optical flaring state of S5 1803+784
ATel #3792; R. Nesci, S. Sclavi (University La Sapienza, Roma, Italy)
on 30 Nov 2011; 19:39 UT
Credential Certification: Roberto Nesci (roberto.nesci@uniroma1.it)
Subjects: Optical, AGN, Blazar
Referred to by ATel #: 13711
The blazar S5 1803+784 is being monitored since many years from our group. Our recent photometry, performed with the remote controlled TACOR telescope of the Department of Physics of La Sapienza University, shows that the source brightened from R=16.2 on 2011-11-16 to R=14.9 on 2011-11-26. This is just one magnitude fainter than the historical maximum for this source (Nesci et al AJ 2002, 124, 53). No corresponding Gamma-ray flare is still apparent in the LAT light curve, publicly available at http://fermi.gsfc.nasa.gov/ssc/data/access/lat/msl_lc/.
The last Gamma-ray flare of S5 1803+784 (at a level of 1E-6 ph/cm2/s) was reported on 2011-05-02 (Atel#3322): in that occasion the optical flux reached R=15.6 (Atel#3323), substantially fainter than the present state: one might expect therefore an even higher flux level at high energies, if the emission mechanisms are related. The previous LAT-reported Gamma-ray flare was around JD 2,455,200 (January 2010) when the source reached R=14.9 according to our monitoring. Further multiwavelength observations are encouraged.
