[vsnet-grb-info 13466] GRB 130606A: RATIR r -band Dropout

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14799
SUBJECT: GRB 130606A: RATIR r'-band Dropout
DATE:    13/06/07 05:46:43 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 130606A (Ukwatta, et al., GCN 14781) 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 2013/06 7.19 to 2013/06 7.20 UTC (7.38 to 7.79
hours after the BAT trigger), obtaining a total of 0.36 hours exposure in
the r' and i' bands and 0.15 hours exposure in the Z, Y, J, and H bands.

The optical/NIR afterglow (Jelinek, et al., GCN 14782; Xu et al., GCN
14783) is quite red and clearly detected in all bands but r'.  In
comparison with SDSS DR9 and 2MASS, we obtain the following detections and
3-sigma upper limit:

r' > 23.02
i' 21.16 +/- 0.06
Z  18.79 +/- 0.03
Y  18.40 +/- 0.03
J  18.32 +/- 0.03
H  17.92 +/- 0.03

These magnitudes are in the AB system and not corrected for Galactic
extinction in the direction of the GRB.  The lack of detection in r' and
relatively faint flux level in i' are consistent with the high-redshift
determined from spectroscopy (Castro-Tirado, et al., GCN 14790, 14796;
Lunnan, et al., GCN 14798).

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