TITLE: GCN CIRCULAR NUMBER: 35277 SUBJECT: GRB 231205A: DDOTI Upper Limits on the Afterglow DATE: 23/12/06 01:21:44 GMT FROM: Kin O. C. L. Mendoza at Instituto de Astronoma, UNAM <koclopez@astro.unam.mx> Océlotl Lopez (UNAM), Alan M. Watson (UNAM), Rosa L. Becerra (UNAM), Margarita Pereyra (UNAM), Nat Butler (ASU), Simone Dichiara (Penn state university), Diego Gonzalez (UNAM), William H. Lee (UNAM), Alexander Kutyrev (GSFC/UMD), Srihari Ravi (ASU) and Eleonora Troja (Tor Vergara Roma) report: We observed the field of the Fermi GBM GRB 231205A (Fermi GBM Team, GCN Circ. 35263) with the DDOTI wide-field imager at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir ( http://ddoti.astroscu.unam.mx) from 2023-12-05 12:55:13 to 13:10:57 UTC (10.50 to 11.75 hours after the trigger). We observed a region of 7 degrees in RA by 7 degrees in declination centered on the Fermi GBM Final Position of RA = 206.1 and Dec = 22.8 (J2000 degrees). This region contains 1 instrumental field or about 49 square degrees. We obtained 13.6 minutes of exposure per instrumental field in the w filter. We obtained AB photometry by calibration against the APASS catalog. We detect no likely candidates for the afterglow to our 10-sigma upper limits of w = 18.89-19.41 (inter-quartile). We thank the staff of the Observatorio Astronómico Nacional on San Pedro Mártir. View this GCN Circular online at https://gcn.nasa.gov/circulars/35277. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...