GCN Circular 17087
Subject
GRB 141121A: Continued RATIR Optical Observations
Date
2014-11-23T07:05:41Z (10 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 22.28 to 2014/11 22.53 UTC (26.79
to 32.94 hours after the BAT trigger), obtaining a total of 4.93 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 20.84 +/- 0.03
i 20.68 +/- 0.03
z > 20.02
These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.
The source has faded in r and i by 1.2 magnitudes or roughly t^-0.73 since
our observations on the first night (Watson et al., GCN 17084), confirming
that it is the afterglow. This fading is steeper than the t^-0.15 fading
seeing during our observations on the first night.
We thank the staff of the Observatorio Astron�mico Nacional in San Pedro
M�rtir.