GCN Circular 30856
Subject
GRB 210919A: LOAO and LSGT optical upper limits
Date
2021-09-20T08:00:38Z (4 years ago)
From
Sophia Kim at Seoul National U. <sophiak@astro.snu.ac.kr>
GRB 210919A: LOAO and LSGT optical upper limits
Sophia Kim (Seoul National University, SNU), Myungshin Im (SNU); Jeff Cooke
(Swinburne University of Technology), Gu Lim (SNU); report on behalf of
IMSNG & GECKO Collaboration
We carried out follow-up observations of GRB210919A (A. Tohuvanohu et al.
GCNC #30846) with the 1-m telescope at Mt. Lemon Optical Astronomy
Observatory (LOAO) in US Arizona. Observations began on September 19 at
10:42:02 UT , ~10.23 hours after the GRB trigger. We took 19 X 180s
exposures in Johnson R-band.
We also observed the same field with the 0.43-meter (17 inch) Lee Sang Gak
Telescope (LSGT) located at the Siding Spring Observatory (SSO) in
Australia. Imaging began on the same day at 16:12:53 UT, ~15.73 hours after
the GRB trigger. The observations were performed in a Sloan r-, i- and
z-band sequences with 11 X 300s exposures in each band.
No GRB optical counterpart was found in the LOAO and LSGT data within the
XRT error area (M. R. Goad et al. GCNC #30850). This result is consistent
with the optical observational results by other teams (V. Lipunov et al.
GCNC #30847, Y.-D. Hu et al. GCNC #30848, R. Strausbaugh et al. GCNC
#30849, M.R. Goad et al. GCNC #30850, N. Pankov et al. GCNC #30851, D. A.
Perley et al. GCNC #30852, M. Perri et al. GCNC #30854 and Y.Takamatsu et
al. GCNC #30855).
The following is our observation results.
We calibrated flux with the PS1 catalog and used AB magnitude system. (The
magnitudes are not corrected for extinction.)
#--------------------------------------------------------------------------------------------------------------
OBS/TEL DATE-OBS(UT) FILTER EXPT UL(3��)[ABmag] UL(5��)[ABmag]
LOAO/1-m 2021-09-19T10:42:02 R 3420s >21.716 >21.162
SSO/LSGT 2021-09-19T16:12:53 r 3300s >20.160 >19.605
SSO/LSGT 2021-09-19T16:18:17 i 3300s >19.107 >18.553
SSO/LSGT 2021-09-19T16:23:53 z 3300s >18.674 >18.119
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[GCN OPS NOTE(20sep2021): Per author's request, the signiture block
that is automatically added to the bottom has been removed.]