TITLE:   GCN CIRCULAR
NUMBER:  26381
SUBJECT: LIGO/Virgo S191205ah: MITSuME Observation of MASTER OT J123123.61-043847.2
DATE:    19/12/07 20:16:44 GMT
FROM:    Katsuhiro L. Murata at Nagoya U  <murata@u.phys.nagoya-u.ac.jp>

Murata, K. L. (Tokyo Institute of Technology); Nakaoka, T. (Hiroshima U.);
Utsumi, Y. (Stanford/SLAC), on behalf of J-GEM collaboration

We report optical follow-up observations for a bright optical transient (V.
Lipunov al., GCN Circ. 26379) inside LVC 191205ah error region (The LIGO
Scientific Collaboration and the Virgo Collaboration, GCN Circ. 26350).

We observed the OT using 50 cm MITSuME telescope at Akeno Observatory using
a 3 color imager in g', Rc, Ic starting at 19:09:08 (UT) on 2019-12-07. We
confirmed the position of the OT is consistent with GCN Circ. 26379.
Our photometry results with an integration time of 1080 sec are:
g' 17.7 +/- 0.1
Rc 17.9 +/- 0.1
Ic 18.6 +/- 0.2
in AB magnitude system calibrated by PanSTARRS photometry of nearby stars.