[vsnet-grb-info 12997] GRB 130327A: RATIR Optical and NIR Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14334
SUBJECT: GRB 130327A: RATIR Optical and NIR Observations
DATE:    13/03/27 04:56:14 GMT
FROM:    Nat Butler at UC berkeley  <natxbutler at gmail.com>

Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC),
William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB),
Ori Fox (UCB) J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino
Cucchiara (UCSC), Eleonora Troja (GSFC), Enrico Ramirez-Ruiz (UCSC),
José A. de Diego (UNAM), Leonid Georgiev (UNAM), Jesús González
(UNAM), Carlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC), and Harvey
Moseley (GSFC) report:

We observed the field of GRB 130327A (Ukwatta, et al., GCN 14331) 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 2013/03 27.12 to 2013/03
27.17 UTC (1.16 to 2.17 hours after the BAT trigger), obtaining a
total of 0.82 hours exposures in the r' and i' bands and 0.35 hours of
exposure in the Z, Y, J, and H bands.

We detect one uncatalogued source within the XRT error region (GCN
14331), at a position RA , DEC: = 92.03875,  55.71504 (+/-0.5 ",
J2000).  This is 2.7" from the center of the XRT error circle.  In
comparison with USNO-B1 and 2MASS, we derive the following detections
and upper limit (3-sigma) in the AB magnitude system:

r'    21.22 +/- 0.10
i'    21.17 +/- 0.09
Z    20.09 +/- 0.14
Y    19.98 +/- 0.17
J    19.98 +/- 0.23
H     > 20.08

We also detect a second uncatalogued source just outside the XRT error
circle (3.9" from the center) at RA , DEC: 92.03822,  55.71326 (+/-0.5
", J2000):

r'    21.61 +/- 0.14
i'    20.36 +/- 0.05
Z    19.15 +/- 0.06
Y    18.72 +/- 0.06
J    18.70 +/- 0.07
H    18.53 +/- 0.09

We note that this second source has a brightness consistent with the
earlier PAIRITEL measurement (Morgan; GCN 14333).

We thank the staff of the Observatorio Astronómico Nacional in San
Pedro Mártir.  Further observations are planned.