GCN Circular 32625
Subject
GRB 220930A: MITSuME Akeno optical upper limits
Event
Date
2022-10-05T08:46:19Z (3 years ago)
Edited On
2025-12-12T18:16:15Z (3 hours ago)
From
Tateda Mahiro at Tokyo Tech <tateda@hp.phys.titech.ac.jp>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov>
M. Tateda, I.Takahashi, K. L. Murata, Y. Imai, N. Ito, M. Niwano, S.
Sato, N. Higuchi, Y. Takamatsu, R. Hosokawa, M. Sasada, Y. Yatsu, and
N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration:We
observed the field of GRB 220930A (S. B. Cenko et al. GCN Circular
#32603, Alan M. Watson et al. GCN Circular #32604, The Swift-XRT team
GCN Circular #32605,, Y.-D. Hu et al. GCN Circular #32606, V. Lipunov
et al. GCN Circular #32607, P.A. Evans et al. GCN Circular #32608, A.
Belles et al. GCN Circular #32609, R. Strausbaugh et al. GCN Circular
#32610, V. D'Elia et al. GCN Circular #32611, S. D. Barthelmy et al.
GCN Circular #32612, R. Gopalakrishnan et al. GCN Circular #32613,
A.Ridnaia et al. GCN Circular #32614, N. Pankov et al. GCN Circular
#32617) with the optical three color (g', Rc, and Ic) CCD cameras
attached to the MITSuME 50 cm telescope Akeno.The observation with a
series of 60 sec exposures started at 2022-09-30 13:10:00 UT (118.1
minutes after the Swift/BAT trigger). We stacked the images with good
conditions. We did not detect any uncatalogued sources within the
enhanced Swift/XRT error region (Evans et al. GCN Circular #32608). We
obtained the 5-sigma limits of the stacked images as follows.T0+[days]
| MID-UT | T-EXP[sec] | 5-sigma limits
------------------------------------------------------------------------------------------------
0.23 | 2022-09-30 16:39:02.52 | 14460 | g'>21.0, Rc>20.9, Ic>20.4
------------------------------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure timeWe used PS1 catalog for flux calibration.
The magnitudes are expressed in the AB system. The images were
processed in real-time through the MITSuME GPU reduction pipeline
(Niwano et al. 2021, PASJ, Vol.73, Issue 1, Pages 4-24;
https://github.com/MNiwano/Eclaire)..