GCN Circular 15192
Subject
GRB 130907A: RATIR Optical and NIR Afterglow Confirmation
Date
2013-09-08T05:11:53Z (11 years ago)
From
Alan M. Watson at Instituto de Astronomia UNAM <alan@astro.unam.mx>
William H. Lee (UNAM), Nat Butler (ASU), Alan M. Watson (UNAM),
Alexander Kutyrev (GSFC), 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), Jos� A. de Diego (UNAM), Leonid Georgiev (UNAM),
Jes�s Gonz�lez (UNAM), Carlos Rom�n-Z��iga (UNAM), Neil Gehrels (GSFC),
and Harvey Moseley (GSFC) report:
We observed the field of GRB 130907A (Page et al., GCN 15183) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio Astron�mico Nacional on
Sierra San Pedro M�rtir from 2013/09 8.14 to 2013/09 8.15 UTC (5.57
to 6.03 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.
We detect a source at 14:23:34.01 +45:36:27.0 J2000 (+/- 0.5") with
r = 20.01 +/- 0.03
i = 19.30 +/- 0.02
Z = 18.78 +/- 0.05
Y = 18.48 +/- 0.06
J = 18.13 +/- 0.06
H = 17.63 +/- 0.05
These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.
This source is outside the Swift-XRT error circle, but is only 0.8
arcsec from the transient source reported by de Ugarte Postigo et al.
(GCN 15187) and 0.2 arcsec from the transient source reported by Trotter
et al. (GCN 15191). From the close positional coincidence and fading
magnitudes (r of 16.7, 19.6, and 20.0), we conclude all three
observations are of the optical transient.
The transient source is 0.5 arcsec from the faint galaxy SDSS
J142333.95+453626.2, but is 1-2 magnitudes brighter in riZ.
We thank the staff of the Observatorio Astron�mico Nacional in San Pedro
M�rtir.