GCN Circular 19196

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

We observed the field of GRB 160314A (D'Elia et al., GCN Circ. 19182
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 2016/03 15.13 to
2016/03 15.36 UTC (15.59 to 21.16 hours after the BAT trigger),
obtaining a total of 3.56 hours exposure in the r and i bands and 1.49
hours exposure in the Z, Y, J, and H bands.

For a source within the Swift-XRT error circle (Osborne et al., GCN
Circ. 19185
Not found
 
 
), in comparison with the SDSS DR9 and 2MASS catalogs, we
obtain the following detections and 3-sigma upper limit:

 r	22.83 +/- 0.10
 i	22.37 +/- 0.06
 Z	22.27 +/- 0.15
 Y	22.40 +/- 0.21
 J	21.93 +/- 0.19
 H	> 22.38

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

Compared to the NOT observations reported by Malesani et al. (GCN Circ.
19191
Not found
 
 
), we detect fading in r at the 3.7-sigma level between mean epochs
of 9.2 and 18.4 hours after the bursts. This confirms that the NOT
source is the optical counterpart of the GRB.

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