GCN Circular 31775
Subject
GRB220319A: Optical observations from NOT
Event
Date
2022-03-20T13:47:37Z (4 years ago)
From
Antonio de Ugarte Postigo at OCA <deugarte@oca.eu>
A. de Ugarte Postigo (OCA) and R. Clavero Jimenez (NOT)
report on behalf of a larger collaboration:
We observed the field of GRB220319A (Page et al. GCN31769)
with the 2.5m Nordic Optical Telescope equipped with AlFOSC.
Observations consisted of 3x300s in r and 5x200s in z. Due to variable
weather conditions, the observation was attempted twice, between
22:12 and 22:47 UT and between 00:10-00:48 UT (starting 4.53 and
6.49 hr after the burst). We also note the high background due to the
illumination from the almost full Moon. The first attempt had a seeing
of 1.5��� in r and 1.3��� in z and was affected by some dome vignetting
due to the low elevation. The second observation had better conditions
with 1.2��� seeing in r and 1.1��� in z.
In a preliminary reduction, we do not detect any new source within or
near the refined XRT position (Goad et al. GCN 31771) in any of the
images. We estimate a 3-sigma limit of z > 21.5 mag in the first epoch
and > 22.5 mag in the second epoch.