[vsnet-grb-info 21687] GRB 190123A: AROMA-N Optical Observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  23786
SUBJECT: GRB 190123A: AROMA-N Optical Observation
DATE:    19/01/24 14:59:31 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto at phys.aoyama.ac.jp>

M. Nakamura, T. Sakamoto (AGU)

We observed the field of GRB 190123A detected by Swift
(D'Ai et al., GCN Circ. 23769) with the 14-inch AGU Robotic
Optical Monitor for Astrophysical object - Narrow (AROMA-N)
located at the Sagamihara campus of Aoyama Gakuin University.

30 images of 60 sec exposures were taken in the R filter
starting from January 23 12:21:49 (UT) about 156 seconds
after the trigger and stopped on January 23 12:58:25 (UT).
We do not detect the optical afterglow both in the individual
images and the stacked image.  The estimated five sigma
upper limit of the combined image (total exposure of 1800 sec)
is ~17.7 mag using the USNO-B1 catalog.