GCN Circular 33217
R. Strausbaugh (University of Minnesota), A. Cucchiara (NASA) report on behalf of a larger collaboration: We observed the GRB 230123A (Williams et al., GCN 33206) field with the LCOGT 1-meter Sinistro instrument at the Cerro Tololo Interamerican Observatory, Chile site, on January 24, from 02:06 to 02:38 UT (corresponding to 15.78 to 16.32 hours from the GRB trigger time) with the Bessel R and I filters. We performed a series of 3x300s exposures in each band. We do not detect a source in either band within the XRT enhanced error region (Beardmore et al., GCN 33209), consistent with other optical upper limits (Gendre et al., GCN 33208; Belles et al., 33211). The following upper limits are calculated using the USNO-B1.0 catalog as reference: R > 20.8 I > 20.1 These magnitudes are not corrected for galactic extinction.