GRB 220412A: RATIR Afterglow Candidate

We observed the field of GRB 220412A (Klingler et al. GCN 31881) with the Reionization and Transients Infrared Camera (RATIR) on the 1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir from 2022/04 12.28 to 2022/04 12.29 UTC (0.1 to 0.5 hours after the BAT trigger), obtaining a total of 0.21 hours exposure in the r and i bands and 0.08 hours exposure in the Z, Y, J, and H bands. We detect a bright, uncataloged source at RA = 123.967275 and declination = 30.342693 degrees (J2000), about 5.5 arcsec to the east of the current Swift XRT SPER position. In comparison with the SDSS DR9 and 2MASS catalogs, we obtain the following magnitudes: r = 19.41 +/- 0.12 i = 19.26 +/- 0.10 Y = 19.11 +/- 0.23 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. Despite being slightly outside the current XRT error region, we suggest that this source is likely to be the afterglow. Observations are continuing. We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir.