TITLE: GCN CIRCULAR NUMBER: 42632 SUBJECT: LIGO/Virgo/KAGRA S251108fi: DDOTI Optical Candidate DATE: 25/11/10 07:18:02 GMT FROM: Rosa Leticia Becerra Godínez at Instituto de Astronomía, UNAM <rbecerra@astro.unam.mx> Rosa L. Becerra (UNAM), Alan M. Watson (UNAM), Camila Angulo Valdez (UNAM), Nat Butler (ASU), Simone Dichiara (Penn State University), Tsvetelina Dimitrova (ASU), Alexander Kutyrev (GSFC/UMD), William H. Lee (UNAM), Océlotl López (UNAM), Margarita Pereyra (UNAM) and Eleonora Troja (U Roma) report: We observe the field of the gravitational wave candidate S251108fi (LVKC, GCN Circ. 42624) with the DDOTI/OAN wide-field imager at the Observatorio Astronómico Nacional on the Sierra of San Pedro Martir (http://ddoti.astroscu.unam.mx) on the night of 2025-11-10 UTC. DDOTI observed from 02:22 UTC to 04:35 UTC (T+31.4 h to T+33.6 h after the trigger), with a total exposure time of 72 minutes, pointing the region reported by the IceCube Collaboration (GCN Circ. 42630). Comparing our observations with the USNO-B1 and Pan-STARRS PS1 DR2 catalogues, we identify an uncatalogued source at: RA = 00:57:11.36 (14.2973 d) DEC= +07:39:07.1 (7.6520 d) with a preliminary magnitude AB magnitude of: w = 20.11 +/- 0.11. This source lies outside the IceCube region but within the 90% credible region reported by the LVK Collaboration (GCN Circ. 42628). It is located approximately 4" from a known galaxy with a photometric redshift of z = 0.214 ± 0.031 in the Legacy Survey DR10 (Dey et al. 2019). If they are associated, such a redshift would make a connection with the GW candidate unlikely. However, further observations and analysis are ongoing. This value is not corrected for the Galactic extinction. We thank the staff of the Observatorio Astronómico Nacional on the Sierra of San Pedro Mártir. View this GCN Circular online at https://gcn.nasa.gov/circulars/42632. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...