[vsnet-grb-info 14050] GRB 131014A: RATIR Optical/NIR Afterglow Retraction

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15364
SUBJECT: GRB 131014A: RATIR Optical/NIR Afterglow Retraction
DATE:    13/10/21 23:39:18 GMT
FROM:    Eleonora Troja at GSFC  <eleonora.troja at nasa.gov>

Eleonora Troja (GSFC), 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), 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 reobserved the field of GRB 131014A (Fitzpatrick, et al., GCN 15332;
Desiante, et al., GCN 15333) 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
from 2013/10 17.36 to 2013/10 17.53 UTC (75.50 to 79.48 hours after the
GBM trigger), and again the next night from 2013/10 18.35 to 2013/10
18.53 UTC (99.18 to 103.48 hours after the GBM trigger), obtaining a
total of 2.3 hours exposure in the r and i bands and 1.0 hours exposure
in the Z, Y, J, and H bands each night.

These observations reach similar depths to prior RATIR observations of the
field (Troja, et al., GCNs 15340, 15346) in which we report a candidate
optical/NIR afterglow, albeit with marginal statistical significance.
Although the optical/NIR candidate afterglow appears fainter in the 2nd
and 3rd nights relative to our 1st night, it is similarly bright in the
4th night as on the 1st night. The co-addition of data from nights 2
through 4 yields flux levels (in all bands) statistically consistent 
with those
measured on night 1. An image subtraction analysis confirms this result.

We conclude that our source is not the optical/NIR afterglow of GRB 
131014A.

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