S5 1803+78 Revisited

We report on our optical monitoring of the BL Lac object S5 1803+78 from 1996 to 2011. The source showed no clear periodicity, but a time scale of about 1 300 days between major flares is possibly present. No systematic trend of the color index with flux variations is evident, at variance with other...

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Bibliographic Details
Main Authors: R. Nesci, A. Maselli, F. Montagni, S. Sclavi
Format: Article
Language:English
Published: CTU Central Library 2012-01-01
Series:Acta Polytechnica
Subjects:
Online Access:https://ojs.cvut.cz/ojs/index.php/ap/article/view/1508
Description
Summary:We report on our optical monitoring of the BL Lac object S5 1803+78 from 1996 to 2011. The source showed no clear periodicity, but a time scale of about 1 300 days between major flares is possibly present. No systematic trend of the color index with flux variations is evident, at variance with other BL Lacs. In one flare, however, the source was bluer in the rising phase and redder in the falling one. Two ?-ray flares were detected by Fermi-GST during our monitoring: on the occasion of only one of them we found simultaneous optical brightening. A one-zone Synchrotron Self Compton (SSC) model appears too simple to explain the source behavior.
ISSN:1210-2709
1805-2363