Optical flare of S5 1803+78
ATel #7933; Roberto Nesci (INAF/IAPS, Roma Italy), Fabio Martinelli and Raffaele Bernacchi( Lajatico Astronomical Center)
on 20 Aug 2015; 22:06 UT
Credential Certification: Roberto Nesci (Roberto.Nesci@iaps.inaf.it)
Subjects: Optical, AGN, Blazar
We observed the Gamma-ray blazar S5 1803+78 on 2015-08-19.83 at R=14.13, with the 50cm F/8.8 telescope of the Lajatico Astronomical Center (Tuscany-Italy) and a Moravian KAF1001E CCD camera. This is the brightest recorded flux level of this source since 1999: the last flare at similar optical level was recorded in 2005, before the launch of the Fermi satellite.
S5 1803+78 is one of the LAT-monitored sources: its weekly quick-look light-curve in the full energy range (100-300000 MeV) reports a gamma-ray flux around 1.5E-7 ph/cm2/s, near its typical quiescent level. We will continue the optical monitoring of this flare: multiwavelength, especially X-ray, observations are requested to better define the emission mechanism of the source during this rare flare state.
