GCN Circular 15321
Subject
GRB 130831A: Continued RATIR Optical and NIR Observations
Date
2013-10-09T21:22:00Z (11 years ago)
Edited On
2024-11-07T18:49:55Z (2 days 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>
William H. Lee (UNAM), Nat Butler (ASU), Alan M. Watson (UNAM),
Alexander Kutyrev (GSFC), 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 130831A (Hagen, et al., GCN 15139) 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 2013/10 9.10 to 2013/10 9.47 UTC (925.41
to 934.19 hours after the BAT trigger), obtaining a total of 6.08 hours
exposure in the r and i bands and 2.61 hours exposure in the Z,
Y, J, and H bands.
For a source within the Swift-XRT error circle, in comparison with 2MASS, we
obtain the following upper limits (3-sigma):
r > 24.14
i > 23.63
Z > 22.94
Y > 22.45
J > 22.23
H > 21.74
These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.
As compared with our previous RATIR observations (Lee et al., GCN 15274) we
confirm the fading in r and i by at least 0.3 and 0.4 and magnitudes, respectively.
The upper limits in Z, Y, J, and H are also consistent with fading.
Overall our measurements (Butler et al. GCN 15165, Watson et al. GCN 15179,
Lee et al., GCN 15242, 15274) are consistent with the re-brightening due to
a SN, as reported by Pozanenko et al. (GCN 15237) and spectroscopically by
Klose et al. (GCN 15320), and fading.
We thank the staff of the Observatorio Astronómico Nacional in San Pedro
Mártir.