[vsnet-grb-info 17479] GRB 160117B: further RATIR observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  18907
SUBJECT: GRB 160117B: further RATIR observations 
DATE:    16/01/20 19:15:17 GMT
FROM:    Antonino Cucchiara at NASA/GSFC  <antonino.cucchiara at nasa.gov>

Antonino Cucchiara(GSFC/STScI),Nat Butler (ASU), Alan M. Watson (UNAM), 
Alexander Kutyrev (GSFC),William H. Lee (UNAM), Michael G. Richer (UNAM), 
Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB),  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 again the field of GRB 160117B (Sonbas et al., GCN 18875)
with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org <http://www.ratir.org/>) 
on the 1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional 
on Sierra San Pedro Mártir from 2016/01 20.21 to 2016/01 20.36 UTC (63.10
to 66.61 hours after the BAT trigger), obtaining a total of 2.51 hours
exposure in the r and i bands.

In comparison with the USNO-B1 and 2MASS catalogs, we
obtain the following detections:

  r	23.04 +/- 0.27
  i	22.20 +/- 0.12 

Also, after further analysis of the RATIR full dataset on GRB 160117B 
from 2016/01 19.19 to 2016/01 19.36 UTC (38.57 to 42.63 hours after the BAT trigger)
we report the following detections in r and i bands: 

  r  22.30 +/- 0.11
  i  21.96 +/- 0.08

The previously reported, incorrect, limits should not to be considered (GCN 18900).

We thank the staff of the Observatorio Astronómico Nacional in San Pedro 
Mártir. We thank D. Malesani, the NOT, and GROND teams for encouraging 
us to reconsider our earlier observations.