Detection of high and variable Optical Polarization in Blazar S5 0716+71 from MIRO
ATel #2347; KS Baliyan, S Ganesh, S Chandra , UC Joshi (PRL)
on 14 Dec 2009; 07:36 UT
Distributed as an Instant Email Notice Request For Observations
Credential Certification: Kiran S Baliyan (baliyan@prl.res.in)
Subjects: Sub-Millimeter, Optical, AGN, Quasar
Referred to by ATel #: 2353
Blazar S5 0716+714 (PKS 0716+71) is highly variable at short and long term timescales in all energy regimes. We monitored it for linear Optical Polarization using 1.2m Telescope at Mt Abu IR Observatory, India, mounted with two-channel PRL Polarimeter. It was found to have high and variable polarization during Dec 12-13, 2009. The source has been reported to be undergoing flaring activity at sub-mm (ATEL #2342) and a multifrequency campaign is already on.
Our preliminary measurements on Dec. 13, 2009 indicate S5 0716+714 to have high linear optical polarization varying from about 13(+/-1.156)% to 18(+/-0.854)% in white light during a period of about three hours (UT 18:52:10 to 22:15:40). It was accompanied with a consistent change in optical EVPA by about 10 deg. Evolution of polarization can indicate the nature of magnetic field in the jet.
We had noticed similar polarization level on December 12, 2009 also, with brightness levels (based on comparison star 5 in the field) of about 12.9 and 13.2 mag in R and V, respectively.
(Mt Abu IR Observatory is operated by the Physical Research Laboratory, Ahmedabad,India, supported by the Department of Space, Government of India.)
