GCN Circular 21121

D. Kuroda, K. Yanagisawa, Y. Shimizu, H. Toda (OAO, NAOJ),
S. Nagayama (NAOJ), M. Yoshida (Subaru, NAOJ), K. Ohta (Kyoto)
and N. Kawai(Tokyo Tech)
report on behalf of the MITSuME and OISTER collaboration:

We observed the field of GRB 170519A (Ukwatta et al., GCNC 21106)
with the optical three color (g', Rc and Ic) CCD camera attached
to the MITSuME 50cm telescope of Okayama Astrophysical Observatory.

The observation started on 2017-05-19 11:03:26 UT (~5.9 h after
the burst). We detected the previously reported afterglow (Ukwatta
et al., GCNC 21106; Izzo et al., GCNC 21108) in all the three bands.

Photometric results of the OT are listed below. We used SDSS-DR8
catalog for flux calibration.

#T0+[day]  MID-UT    T-EXP[sec]   g'  g'_err  Rc  Rc_err  Ic  Ic_err
------------------------------------------------------------------
0.26646    11:33:44    3120.0    19.1  0.2   18.7 0.2   18.1  0.2
------------------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]