GCN Circular 15462

Owen Littlejohns (ASU), 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 (ORAU/GSFC),
Eleonora Troja (GSFC), 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 again observed the field of GRB 131030A (Troja, et al., GCN Circ.
15402
Not found
 
 
) 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
2013/11 5.08 to 2013/11 5.34 UTC (124.95 to 131.33 hours after the
BAT trigger), obtaining a total of 4.24 hours exposure in the r and
i bands and 0.92 hours exposure in the Z, Y, J, and H bands.

We continue to detect the previously reported source in the r and i
bands (Littlejohns, et al., GCN Circ. 15420
Not found
 
 
; Troja, et al., GCN Circ.
15402
Not found
 
 
). For a source within the Swift-XRT error circle, in comparison
with the SDSS DR9 and 2MASS, we obtain the following detections and
upper limits (3-sigma):

  r     23.17 +/- 0.14
  i     22.73 +/- 0.14
  Z     > 22.82
  Y     > 22.35
  J     > 20.05
  H     > 19.38

A further epoch of observations was also conducted from 2013/11 6.09
to 2013/11 6.34 UTC (149.15 to 155.17 hours after the BAT trigger),
obtaining a total of 3.73 hours exposure in the r and i bands and 1.53
hours exposure in the Z, Y, J, and H bands. The source was detected in
the r and i bands once more. For a source within the Swift-XRT error
circle, in comparison with the SDSS DR9 and 2MASS, we obtain the
following detections and upper limits (3-sigma):

  r     23.41 +/- 0.18
  i     23.06 +/- 0.18
  Z     > 22.74
  Y     > 22.25
  J     > 21.97
  H     > 21.39

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB. In comparison with previous
epochs of RATIR observations, the source continues to fade in both the
r and i band.

We thank the staff of the Observatorio Astron�mico Nacional in San Pedro
M�rtir.