GCN Circular 23307

Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC),
William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J.
Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI),
Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz
(UCSC), Jes��s Gonz��lez (UNAM), Carlos Rom��n-Z����iga (UNAM), Harvey
Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (U. Wash.), and Vicki
Toy (UMD) report:

We observed the field of GRB 181003A (Beardmore et al., GCN Circ. 23295
Not found
 
 
)
with the Reionization and Transients Infrared Camera (RATIR;
www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio
Astron��mico Nacional on Sierra San Pedro M��rtir from 2018/10 4.32 to
2018/10 4.46 UTC (26.59 to 29.89 hours after the BAT trigger), obtaining
a total of 1.41 hours exposure in the r and i bands and 0.58 hours
exposure in the Z, Y, J, and H bands.

For a source within the Swift-XRT error circle (Tohuvavohu et al., GCN
Circ. 23305
Not found
 
 
), in comparison with the USNO-B1 and 2MASS catalogs, we
obtain the following 3-sigma upper limits:

  r	> 23.40
  i	> 23.15
  Z	> 22.01
  Y	> 21.53
  J	> 21.19
  H	> 20.73

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.

We thank the staff of the Observatorio Astron��mico Nacional in San Pedro
M��rtir.