[vsnet-grb-info 24022] GRB 191031D: RATIR Optical and NIR Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  26121
SUBJECT: GRB 191031D: RATIR Optical and NIR Observations 
DATE:    19/11/01 04:40:51 GMT
FROM:    Alan M Watson at UNAM  <alan at astro.unam.mx>

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), Jesús González (UNAM), Carlos
Román-Zúñiga (UNAM), Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou
(U. Wash.), and Vicki Toy (UMD) report:

We observed the field of GRB 191031D (Fermi GBM Team, GCN Circ. 26111; D'Elia et
al., GCN Circ. 26112) 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 2019/11 1.09 to 2019/11
1.12 UTC (4.65 to 5.49 hours after the BAT trigger), obtaining a total of 0.56
hours exposure in the r and i bands, 0.23 hours exposure in the Z and Y
bands, and 0.06 hours exposures in the J and H bands.

For a source within the Swift-XRT error circle, in comparison with the USNO-B1
and 2MASS catalogs, we obtain the following upper limits (3-sigma):

  r	> 22.94
  i	> 23.17
  Z	> 21.50
  Y	> 21.40
  J	> 19.44
  H	> 19.33

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.

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