TITLE:   GCN CIRCULAR
NUMBER:  31826
SUBJECT: GRB 220403B: LBT observations
DATE:    22/04/04 06:11:24 GMT
FROM:    Andrea Rossi at INAF  <andrea.rossi@inaf.it>

A Rossi (INAF-OAS) report on behalf of the CIBO collaboration:

We observed the field of GRB 220403B (Klingler et al., GCN 31820) 
simultaneously in the g',r',i' and z' bands with the LBC imager mounted 
on LBT (Mt Graham, AZ, USA). We obtained 10min of imaging at the midtime 
04:02 UT on 2022-04-04, 0.3 days after the burst trigger. Observations 
were performed under good weather conditions with an average seeing of 
~1.5".

We clearly detect the afterglow and we preliminary measure

r=20.9+-0.1 (AB system),

calibrated against Pan-STARRS field stars.

We acknowledge the excellent support from the LBTO and LBT-INAF staff, 
particularly A. Cardwell and S. Allanson in obtaining these observations.