[vsnet-grb-info 17756] GRB 160314A: RATIR Optical and NIR Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19196
SUBJECT: GRB 160314A: RATIR Optical and NIR Observations 
DATE:    16/03/15 20:32:00 GMT
FROM:    Alan M. Watson at Instituto de Astronomia UNAM  <alan at astro.unam.mx>

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), José A. de Diego (UNAM), Leonid Georgiev (UNAM),
Jesús González (UNAM), Carlos Román-Zúñiga (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)
with the Reionization and Transients Infrared Camera (RATIR;
www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio
Astronómico Nacional on Sierra San Pedro Mártir 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), 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), 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 Astronómico Nacional in San Pedro
Mártir.