[ Previous | Next ]
ATEL # 1892; Y. Ikejiri, M. Yamanaka, H. Takahashi, M. Uemura, K. S. Kawabata, K. Sakimoto, H. Yasuda, Y. Fukazawa, T. Ohsugi (Hiroshima University), on behalf of the KANATA team and the Fermi LAT Collaboration
on 5 Jan 2009; 19:49 UT
Password Certification: Hiromitsu Takahashi (firstname.lastname@example.org)
Subjects: Optical, AGN, Quasars
Following the Fermi/LAT detection of the gamma-ray flare from J123939+044409 (ATEL #1888), we performed optical photopolarimetric observations with the "KANATA" 1.5-m telescope at Higashi-Hiroshima Observatory.
Our preliminary analysis shows that the V-band magnitude of SDSS J123932.75+044305 (a possible counterpart of the LAT source J123939+044409) was 15.7+/-0.1 and 16.1+/-0.1 on 2.8 and 3.8 (UT) Jan 2009, respectively. The V-band magnitudes of the object were obtained with a comparison star located at RA=12:39:30.08, Dec=+04:39:53.2 (V=13.320; NOMAD). We confirmed the flare of the object, and the flare amplitude (~5 mag) is almost in agreement with the U-band one reported by the Swift-UVOT observation in ATEL #1888.
The degree of polarization of the object was 9.6+/-2.0 and 2.5+/-0.5 % on 2.8 and 3.8 Jan, respectively, which are not very high compared with the other blazars in large amplitude flares (cf. http://kanatatmp.g.hatena.ne.jp/kanataobslog/ ).
We will continue the optical monitoring of this source.