GCN Circular 24946
Rosa L. Becerra (UNAM), Alan M. Watson (UNAM), Nat Butler (ASU), Diego Gonz��lez (UNAM),Alexander Kutyrev (GSFC), William H. Lee (UNAM), Margarita Pereyra (UNAM), and Eleonora Troja (GSFC) report: We observed the field of GRB 190701A (Ukwatta et al., GCN Circ. 24934) with the COATLI 50-cm telescope and interim imager at the Observatorio Astron��mico Nacional on the Sierra de San Pedro M��rtir (http://coatli.astroscu.unam.mx) from 2019-07-01 09:47:03 to 10:05:06 (from 25.6 seconds after the alert or 103 seconds to 0.33 hours after the trigger), obtaining a total of 490 seconds of exposure in the w filter. Comparing to the USNO and Pan-STARRS1 catalogs, we do not detect any new sources brighter than w = 20.99 (3-sigma limiting mag) in the XRT error region (Osborne et al., GCN Circ. 24940). Our w magnitudes are calibrated against the Pan-STARRS1 catalog, are on an approximate AB system, and are not corrected for Galactic extinction in the direction of the GRB. We thank the COATLI technical team and the staff of the Observatorio Astron��mico Nacional.