[vsnet-grb-info 19225] GRB 170317A: RATIR Optical and NIR Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  20911
SUBJECT: GRB 170317A: RATIR Optical and NIR Observations
DATE:    17/03/18 17:10:21 GMT
FROM:    Nat Butler at UC berkeley  <natxbutler at gmail.com>

Alan M. Watson (UNAM), Nat Butler (ASU), 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 (ASU), and Vicki Toy (UMD)
report:

We observed the field of GRB 170317A (LaPorte et al., GCN 20885) 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 2017/03 18.13 to 2017/03 18.30 UTC (17.37 to
21.38 hours after the BAT trigger), obtaining a total of 2.84 hours
exposure in the r and i bands and 1.19 hours exposure in the Z, Y, J, and H
bands.

For a source within the enhanced Swift-XRT error circle (Beardmore et al.,
GCN 20887), in comparison with the USNO-B1 and 2MASS catalogs, we obtain
the following detections and 3-sigma upper limits:

  r     22.85 +/- 0.05
  i     22.86 +/- 0.09
  Z     22.92 +/- 0.30
  Y     22.34 +/- 0.26
  J     22.41 +/- 0.35
  H     > 21.95

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.