[vsnet-grb-info 24702] GRB 200115A: AROMA-N Optical Observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  26801
SUBJECT: GRB 200115A: AROMA-N Optical Observation
DATE:    20/01/17 12:46:20 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto at phys.aoyama.ac.jp>

M. Nakamura, T. Sakamoto (AGU)

We observed the field of GRB 200115A detected by Swift
(Cenko et al., GCN Circ. 26771) with the 14-inch AGU Robotic
Optical Monitor for Astrophysical object - Narrow (AROMA-N)
located at the Sagamihara campus of Aoyama Gakuin University.

60 images of 60 sec exposures were taken in the R filter
starting from January 15 12:14:42 (UT) about 24 minutes
after the trigger and stopped on January 15 13:27:55 (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 3600 sec)
is ~18.1 mag using the USNO-B1 catalog.