[vsnet-grb-info 18701] GRB 161108A: RATIR Afterglow Confirmation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  20149
SUBJECT: GRB 161108A: RATIR Afterglow Confirmation
DATE:    16/11/08 14:29:23 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 (UVI), 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 161108A (Beardmore, et al., GCN 20145) 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 2016/11 8.48 to 2016/11 8.54 UTC (7.87 to
9.34 hours after the BAT trigger), obtaining a total of 1.03 hours exposure
in the r and i bands and 0.40 hours exposure in the Z, Y, J, and H bands.

The afterglow candidate reported by Malesani et al. (GCN 20146) is well
detected.  In comparison with the SDSS DR9 and 2MASS catalogs, we obtain
the following detections and upper limits (3-sigma):

  r = 21.97 +/- 0.12
  i = 21.36 +/- 0.06
  Z = 20.88 +/- 0.11
  Y = 20.57 +/- 0.14
  J = 20.05 +/- 0.27
  H > 18.12

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.  The source appears to have faded
in r by about 1 magnitude as compared to Malesani et al. (GCN 20146).

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