TITLE:   GCN CIRCULAR
NUMBER:  16952
SUBJECT: GRB 141026A: RATIR Optical Observations
DATE:    14/10/26 05:47:05 GMT
FROM:    Owen Littlejohns at Az State U  <olittlej@asu.edu>

Owen Littlejohns (ASU), Nat Butler (ASU), Antonino Cucchiara
(ORAU/GSFC), 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), 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 141026A (Hagen, et al., GCN 16950)
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
26.13 to 26.20 UTC (0.54 to 2.20 hours after the BAT trigger),
obtaining a total of 1.07 hours exposure in the r and i bands.

For a source within the Swift-XRT error circle, we obtain the
following upper limits (3-sigma):

  r     > 23.50
  i     > 23.56

These magnitudes are in the AB system and are not corrected for
Galactic extinction in the direction of the GRB.

We do not detect the source observed by P60 (Perley, et al., GCN
16951). We do, however, detect a source at the edge of the Swift-
XRT error circle at RA(J2000) = 44.084036, Dec(J2000) = 26.928134.

  r     21.67 +/- 0.08
  i     21.52 +/- 0.07

We cannot presently determine if this source is fading.

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