GCN Circular 27265

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 200227A (Laha et al., GCN Circ. 27234
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 2020/02 28.17 to 2020/02 28.24
UTC (20.84 to 22.53 hours after the BAT trigger), obtaining a total of
0.69 hours exposure in the r and i bands.

For a source within the Swift-XRT enhanced error circle (Beardmore et
al., GCN Circ. 27243
Not found
 
 
), in comparison with the SDSS DR9, we obtain the
following upper limits (3-sigma):

  r	> 19.73
  i	> 20.33

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.