[vsnet-grb-info 17777] GRB 160321A: Possible RATIR Optical and NIR Detections

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19218
SUBJECT: GRB 160321A: Possible RATIR Optical and NIR Detections
DATE:    16/03/22 17:14:25 GMT
FROM:    Nat Butler at Az State U  <natbutler at asu.edu>

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 160321A (Stamatikos, et al., GCN 19211) 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 22.14 to 2016/03 22.29 UTC (11.32
to 15.08 hours after the BAT trigger), obtaining a total of 2.47 hours
exposure in the r and i bands and 0.82 hours exposure in the Z, Y, J, and H
bands.

For a source within the Swift-XRT error circle (Beardmore, et al., GCN
19213), in comparison with the USNO-B1 and 2MASS catalogs, we obtain the
following weak detections and upper limits (3-sigma):

 r > 23.84
 i = 22.32 +/- 0.11
 Z = 22.49 +/- 0.34
 Y > 22.19
 J > 21.53
 H > 21.27

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

We thank the staff of the Observatorio Astronómico Nacional in San Pedro
Mártir.