[vsnet-grb-info 13912] GRB 130912A: RATIR Optical and NIR Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15226
SUBJECT: GRB 130912A: RATIR Optical and NIR Upper Limits
DATE:    13/09/13 15:25:38 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), Chris Klein (UCB), Ori Fox (UCB),
J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UCSC),
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), and Harvey Moseley (GSFC)
report:

We observed the field of GRB 130912A (D'Elia et al., GCN 15212) 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 2013/09 13.30 to 2013/09 13.49 UTC (22.58 to
27.11 hours after the BAT trigger), obtaining a total of 5.33 hours
exposure in the r and i bands and 2.24 hours exposure in the Z, Y, J, and H
bands.

For a source within the Swift-XRT error circle, in comparison with USNO-B1
and 2MASS, we obtain the following upper limits (3-sigma):

  r     > 23.89
  i     > 23.79
  Z     > 22.86
  Y     > 22.38
  J     > 22.30
  H     > 21.78

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.    Our observations confirm that
the source faded
and is therefore the short GRB afterglow.

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