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ATEL # 1502; V.Larionov, T.Konstantinova, E.Kopatskaya, L.Larionova, N.Efimova, D.Blinov, D.Melnichuk, I.Troitsky (Astronomical Institute of St.Petersburg University, Russia)
on 1 May 2008; 19:14 UT
Password Certification: V.Larionov (email@example.com)
Subjects: Request for Observations, AGN, Black Holes, Quasars
We intensified our monitoring observations of S5 0716+71 following GASP (GLAST-AGILE Support Program of the Whole Earth Blazar Telescope) alert (see also ATEL #1495, #1500). Dense intranight optical photometry and polarimetry have shown that immediately after optical maximum the positional angle of polarization (EVPA) started to rotate with approximate rate 60 degrees per day. This may correspond to the propagation of a polarized knot spiraling down the jet (as in the case of BL Lac, see Marscher et al., 2008, Nature, 452, 966). After six days of smooth rotation (April 19-25) by about 320 degrees relative to pre-outburst level the EVPA stabilized to a value close to the parsec scale jet direction. Farther polarimetric observations are encouraged.