GCN Circular 17742

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

We observed the field of GRB 150423A (Pagani et al., GCNC 17728)
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 2015-04-23 17:04:40 UT, (~10.6 h after the burst).
We could not detect the previously reported afterglow (Varela et al., GCNC
17729,17732; Perley, GCNC 17233) in all the three bands.

Three sigma upper limits of the OT are listed below.
We used SDSS-DR8 catalog for flux calibration.

#T0+[day]  MID-UT    T-EXP[sec]   g'     Rc     Ic
-----------------------------------------------------
0.49107    18:15:13    7200.0   >20.8  >20.8  >19.9
-----------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]