GCN Circular 14409
Subject
GRB 130420A: RATIR Optical and NIR Observations
Date
2013-04-20T11:56:25Z (12 years ago)
Edited On
2024-11-07T18:53:42Z (a month ago)
From
Alan M. Watson at Instituto de Astronomia UNAM <alan@astro.unam.mx>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Leo P. Singer at NASA/GSFC <leo.p.singer@nasa.gov>
Alan M. Watson (UNAM), Nat Butler (ASU), 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 (UCSC), Eleonora Troja (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 observed the field of GRB 130420A (Page, et al., GCN 14406) 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 2013/04 20.41 to 2013/04 20.45 UTC (2.48
to 3.38 hours after the BAT trigger), obtaining a total of 0.36 hours
exposure in the r' and i' bands and 0.14 hours exposure in the Z,
Y, J, and H bands.
For a source within the Swift-XRT error circle, in comparison with SDSS DR8
and 2MASS, we find:
r' 19.81 +/- 0.02
i' 19.41 +/- 0.02
Z 19.37 +/- 0.06
Y 18.99 +/- 0.07
J 19.16 +/- 0.07
H 18.87 +/- 0.11
These magnitudes are in the AB system and not corrected for Galactic
extinction in the direction of the GRB. Uncertainties are 1-sigma.
Comparison to the earlier photometry of Morgan et al. (GCN 14408) shows that this source has faded by about 2.5 magnitudes in J and H.
We thank the staff of the Observatorio Astronómico Nacional in San Pedro
Mártir.
--
Dr. Alan M. Watson
Instituto de Astronomía
Universidad Nacional Autónoma de México