[vsnet-grb-info 17558] GRB 160131A: RATIR Optical Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  18988
SUBJECT: GRB 160131A: RATIR Optical Observations
DATE:    16/02/04 16:54:53 GMT
FROM:    Nat Butler at Az State U  <natbutler at asu.edu>

Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William
H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), 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 160131A (Page, et al., GCN 18951) 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 2016/02 4.10 to 2016/02 4.36 UTC (89.96 to
96.25 hours after the BAT trigger), obtaining a total of 4.60 hours
exposure in the r, i, and z bands.

For a source within the Swift-XRT error circle (Osborne, et al., GCN
18958), in comparison with the USNO-B1 and 2MASS catalogs, we obtain the
following detections and upper limit (3-sigma):

  r = 21.64 +/- 0.05
  i = 21.41 +/- 0.03
  z > 20.48

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.  We note that there is a faint,
possible source present in the DSS near this source which could be the GRB
host galaxy.

We thank the staff of the Observatorio Astronómico Nacional in San Pedro
Mártir.