GCN Circular 17101
Subject
GRB 141121A: Continued RATIR Optical Observations
Date
2014-11-26T16:47:33Z (9 years ago)
From
Alan M. Watson at Instituto de Astronomia UNAM <alan@astro.unam.mx>
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), 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 141121A (Lien et al., GCN 17075) 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 2014/11 26.31 to 2014/11 26.53
UTC (123.55 to 128.80 hours after the BAT trigger), obtaining a total of
4.04 hours exposure in the r, i and z bands.
For a source within the Swift-XRT error circle, in comparison with the
SDSS DR9, we obtain the following detections and upper limits (3-sigma):
r = 21.27 +/- 0.04
i = 21.04 +/- 0.04
z > 21.04
These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.
The afterglow has faded by about 0.3 magnitudes in r and i compared to
our observations at 102 hours (Watson et al., GCN 17100). This
corresponds to a further steepening of the temporal power law from
t^-0.9 between 78 and 102 hours (Watson et al., GCN 17100) to t^-1.3
between 102 and 126 hours.
We thank the staff of the Observatorio Astron�mico Nacional in San Pedro
M�rtir.