[vsnet-grb-info 25345] GRB 200324A: AROMA-N Optical Observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  27445
SUBJECT: GRB 200324A: AROMA-N Optical Observation
DATE:    20/03/26 06:44:11 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto at phys.aoyama.ac.jp>

M. Nakamura, T. Sakamoto (AGU)

We observed the field of GRB 200324A detected by Swift
(Dichiara et al., GCN Circ. 27428) with the 14-inch AGU Robotic
Optical Monitor for Astrophysical object - Narrow (AROMA-N)
located at the Sagamihara campus of Aoyama Gakuin University.

22 images of 60 sec, 120 sec, 180 sec and 300 sec exposures
were taken in the R filter starting from March 24 16:42:55 (UT)
about 228 seconds after the trigger and stopped on March 24 19:06:11 (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 3240 sec) is ~17.6 mag
using the USNO-B1 catalog.