Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 25854

GRB 190926A: MITSuME Akeno optical upper limits
2019-09-27T03:33:15Z (5 years ago)
Adachi Ryo at Tokyo Institute of Tech <>
R. Adachi, K. L. Murata, M. Oeda, K.Shiraishi, K. Iida, M. Niwano,
F. Ogawa, R. Hosokawa, S. Toma, Y. Yatsu, and N. Kawai (TokyoTech)
report on behalf of the MITSuME collaboration:

We searched for the optical counterpart of GRB 190926A (A. Melandri et
al., GCN Circular #25848) with the optical three color (g', Rc, and
Ic) CCD cameras attached to the MITSuME 50 cm telescope of Akeno
Observatory, Yamanashi, Japan.
The observation started on 16:16:33 UT. We did not find any new point
sources within the XRT circle (M.R. Goad et al., GCN Circular #25850)
in all three bands.
We obtained the following 5-sigma limits for the magnitudes.

T0+[hour]   MID-UT    T-EXP[sec]    5-sigma limits
 ~7.0         18:13:34    6960              g'>19.8, Rc>19.5, Ic>19.2
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used UCAC4 catalog for flux calibration.
The magnitudes are expressed in the AB system.
Looking for U.S. government information and services? Visit