GCN Circular 30079
A. Rossi, E. Palazzi, F. Cusano (INAF-OAS) report on behalf of the GRAWITA collaboration: We observed the field of ZTF21aayokph/AT2021lfa (Yao et al., GCN 29938) simultaneously in the r' and z' bands with the LBC imager mounted on LBT (Mt Graham, AZ, USA). We obtained 20min of imaging on 2021-05-11 and starting at 6:26 UT, 6 days after the first communication by ZTF. Observations were performed under good weather conditions with an average seeing of ~1.1". We clearly detect the host galaxy at the position of the afterglow and we preliminary measure the following AB magnitudes r=23.9+-0.1 z=24.1+-0.2 calibrated against SDSS field stars. We acknowledge the excellent support from the LBTO and LBT-INAF staff, particularly A Cardwell, S. Allanson, and D. Paris, in obtaining these observations.