TITLE:   GCN CIRCULAR
NUMBER:  31967
SUBJECT: GRB 220427A: VLT/X-shooter photometry
DATE:    22/04/29 10:10:21 GMT
FROM:    Antonio de Ugarte Postigo at OCA  <deugarte@oca.eu>

A. de Ugarte Postigo (Artemis/OCA), H. Fausey (George Washington
University), D. A. Kann (HETH/IAA-CSIC), D. B. Malesani (Radboud
Univ. and DAWN/NBI), P. Jakobsson (U. of Iceland), A. Saccardi
(GEPI, Observatoire de Paris) and B. Schneider (CEA Paris-Saclay),
report on behalf of the Stargate Consortium:

We observed the field of GRB 220427A (D'Ai et al., GCN 31960)
using the ESO VLT UT3 (Melipal) equipped with the X-shooter
spectrograph. In images taken with the acquisition camera 7.9 hr
after the GRB we measure for the optical afterglow the following
AB magnitudes (calibrated against 2 field stars from the SkyMapper
catalogue):

g' = 22.40 +/- 0.09 mag
r' = 22.04 +/- 0.08 mag
z' = 20.81 +/- 0.08 mag

No useful spectroscopy could be secured.

We acknowledge excellent support from the ESO observing staff in
Paranal, in particular Jonathan Smoker and Rob van Holstein.