GCN Circular 18512
Subject
GRB 151027B: RATIR Observations
Date
2015-10-28T14:10:19Z (9 years ago)
Edited On
2024-11-07T19:53:09Z (19 days ago)
From
Nat Butler at UC berkeley <natxbutler@gmail.com>
Edited By
Vidushi Sharma at NASA GSFC/UMBC <vidushi.sharma@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), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (GSFC/STScI), 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), Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD) report:
We observed the field of GRB 151027B (Ukwatta et al., GCN 18499) 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 2015/10 28.26 to 2015/10 28.51 UTC (7.46 to 13.55 hours after the BAT trigger), obtaining a total of 3.51 hours exposure in the r, i, and z bands.
We detect a source at 05:04:52.69 -06:27:00.8 (J2000, +/-0.05), within the Swift-XRT error circle. In comparison with the USNO-B1 and 2MASS catalogs, we obtain the following detections:
r = 20.83 +/- 0.05
i = 20.18 +/- 0.04
z = 19.49 +/- 0.21
These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB.
This source coincides with the source reported by Malesani et al. (GCN 18501), Xu et al. (GCN 18505), Wiseman et al. (GCN 18507), and Buckley et al. (GCN 18511). The source appears to have faded since these earlier observations and furthermore fades by about 0.5 mag in i over the course of our observations.
We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir.