GCN Circular 19652
Subject
GRB 160703A: MITSuME Akeno Optical Observations
Date
2016-07-04T17:56:53Z (8 years ago)
From
Taketoshi Yoshii at Tokyo Tech <yoshii.t.ac@m.titech.ac.jp>
Y. Tachibana, Y. Saito, Y. Muraki, Y. Ono, T. Fujiwara, T. Yoshii, K. Saisho,
H. Ohuchi, Y. Yano, S. Harita, Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:
We report the optical follow-up observations of GRB 160703A (S. B. Cenko et al., GCN Circular #19645) with a tricolor camera (g', Rc, and Ic) attached to the MITSuME 50 cm telescope of Akeno Observatory, Yamanashi, Japan.
The observation started at 2016-07-03 12:10:54 UT (~30 sec after the burst).
Although the first eight frames (each exposure time is 30 sec) are covered by thick clouds, we detected a bright optical transient source in the refined BAT error circle (A. Y. Lien et al., GCN Circular #19648) ~5 min after the trigger.
The position of the counterpart is
RA(J2000) = 19h 09m 40.1s
Dec(J2000) = +36d 55' 08.1"
with an uncertainty of ~0.5 arc sec.
Nearby the optical transient, a known source N2JN062852 (RA, Dec = 19h 09m 40.212s, +36d 55' 06.9816$B!I(B)
catalogued in GSC2.3 is located.
In the photometric analysis, we ignored the contamination from the nearby source because its
flux is substantially lower (Fmag = 20.27) comparing with the optical counterpart.
The results were shown below:
T0+[min] MID-UT T-EXP[sec] g$B!G(B g$B!G(B_err Rc Rc_err Ic Ic_err
----------------------------------------------------------------------------------------------------------------------
5.82 12:15:54 30 15.46 0.06 14.59 0.06 14.25 0.09
58.35 13:08:26 3900 18.18 0.05 17.08 0.04 16.87 0.06
330.52 15:40:36 7680 19.13 0.06 17.96 0.05 17.61 0.06
----------------------------------------------------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used GSC2.3 catalog for flux calibration.
Further analysis is ongoing.