TITLE: GCN CIRCULAR NUMBER: 32927 SUBJECT: GRB 221110A: COATLI Afterglow detection DATE: 22/11/10 04:49:36 GMT FROM: Emma Margarita Pereyra Talamantes at IA-UNAM Ensenada *Margarita Pereyra (UNAM), Alan M. Watson (UNAM), Nat Butler (ASU), Rosa Becerra (UNAM), Simone Dichiara (PSU), Tzveti Dimitrova (ASU), Océlotl López (UNAM), Diego González (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Eleonora Troja (UTV/ASU) and report:We observed the field of the GRB 221110A (Williams et al., GCN Circ. 32925) with the COATLI 50-cm telescope and HUITZI f/8 imager at the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir (http://coatli.astroscu.unam.mx ) from 2022-11-10 03:26 UTC to 03:59 UTC (0.96hrs to 1.5 hours after the trigger), obtaining a total of 29 minutes of exposure in the r filter.At the position of the UVOT afterglow (Williams et al., GCN Circ. 32925), we detect a source with the following magnitude and 1-sigma uncertainty:r = 19.7 +/- 0.15Our photometry is calibrated against the Pan-STARRS1 catalog, is on an approximate AB system, and is not corrected for Galactic extinction in the direction of the GRB.Observations and reductions will continue. Further observations are planned.We thank the COATLI/HUITZI technical team and the staff of the Observatorio Astronómico Nacional.* -- *Dr. Margarita Pereyra * *FFTF, Schlumberger Foundation Alumnae* ---------------------------------------------------------------------------------------------------------------- *Catedrática Conacyt* *Instituto de Astronomía de la UNAM,* *Km. 107 Carretera Tijua**na-Ensenada, * *Ensenada Baja California, México. C.P. 22860* Oficina: 405 Skype: margarita-pereyra