TITLE: GCN CIRCULAR NUMBER: 22718 SUBJECT: GRB 180512A: LBT optical detection DATE: 18/05/13 13:13:01 GMT FROM: Andrea Rossi at INAF A. Rossi and E. Palazzi (INAF-OAS) report on behalf of the CIBO colaboration: We observed the field of GRB180512A (Swift trigger 832119; Deich et al., GCN #22710) simultaneously in r' and z' bands with the LBC imager mounted on LBT (Mt Graham, AZ, USA). Observations started at 04:05 UT on 2018-05-13, 6 hrs after the GRB trigger and finished at 04:27 UT and allowed us to obtain 20min of exposure in each band. Image inspection reveals a faint source within the Swift/XRT enhanced error circle (Evans et al., GCN 22715) with coordinates: RA(J2000) = 13:27:45.130 Dec(J2000)= +21:24:13.39 with an uncertainty of 0.2" in each coordinate. The source is detected only r'-band and has magnitude r' = 25.0 mag +-0.3 (AB), calibrated against r'-band SDSS field stars. No statement about the variability can be made at this point. Further observations are planned. No correction for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V)=0.02 mag in the direction of the burst (Schlafly & Finkbeiner 2011) has been applied. We acknowledge the excellent support from the LBT-INAF staff, particularly F. Cusano and A. Gargiulo in obtaining these observations.