TITLE:   GCN CIRCULAR
NUMBER:  32972
SUBJECT: GRB 221120A: GTC Confirmation of an Underlying Galaxy
DATE:    22/11/22 23:02:37 GMT
FROM:    Brendan O'Connor at UMD  <oconnorb@umd.edu>

B. O'Connor (UMD/GWU), N. Butler (ASU), A. Watson (UNAM),
E. Troja (UTV/ASU), S. Dichiara (PSU), on behalf of a
larger collaboration:

We observed the short GRB 221120A (Eyles-Ferris et al., GCN 32955,
Tohuvavohu et al., GCN 32959) using OSIRIS at the 10.4m Gran Telescopio
Canarias (GTC). The observation started on November 22, 2022 at
00:44:32 UTC (~1.13 d) for a total exposure of 540 s in r-band.

At the location of the source reported by O'Connor et al. (GCN 32957)
we detect a source with magnitude r~24.38+/-0.08 AB mag calibrated using
nearby SDSS stars. This serves as confirmation of the underlying galaxy
(Rastinejad et al., GCN 32965) and demonstrates a lack of fading of the
source found by O'Connor et al. (GCN 32957). While the host association
is unclear, if this galaxy is associated to GRB 221120A, the observed
r-J color (Karambelkar et al., GCN 32967) suggests that GRB 221120A was
a distant event (see, e.g., O'Connor et al. 2022, MNRAS, 515, 4890).

We thank the GTC staff for rapidly scheduling and executing these
observations.