TITLE: GCN CIRCULAR NUMBER: 35399 SUBJECT: GRB 231216A: optical upper limits from the INAF Asiago Observatory DATE: 23/12/18 16:58:09 GMT FROM: Paolo D'Avanzo at INAF-OAB <pda.davanzo@gmail.com> A. Reguitti (INAF-OAB / INAF-OAPd), P. D'Avanzo (INAF-OAB), I. Salmaso (INAF -OAPd), E. Cappellaro (INAF -OAPd), report on behalf of the CIBO and of the GRAWITA collaborations: We observed the field of GRB 231216A (Sbarrato et al., GCN Circ. 35378) from the INAF - Padova Astronomical Observatory located in Asiago (Italy) with the 1.8m Copernico telescope starting on 2023-12-16 at 20:24:48 UT (~ 1.8 hours after the burst). The observations have been carried out with the AFOSC camera in imaging mode using the r filter. No optical afterglow candidate is detected within the XRT error circle (Sbarufatti et al., GCN Circ .35391) down to a 3sigma limiting magnitude of r ~ 22.0 (AB; calibrated against the PanSTARRS catalogue). View this GCN Circular online at https://gcn.nasa.gov/circulars/35399. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...