[vsnet-grb-info 21136] GRB 180914A: RATIR Optical and NIR Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  23235
SUBJECT: GRB 180914A: RATIR Optical and NIR Observations
DATE:    18/09/15 19:44:14 GMT
FROM:    Eleonora Troja at GSFC  <eleonora.troja at nasa.gov>

Eleonora Troja (GSFC), 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), Owen Littlejohns (ASU), Enrico
Ramirez-Ruiz (UCSC), Jesus Gonzalez (UNAM), Carlos Roman-Zuniga (UNAM),
Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (U. Wash.),
and Vicki Toy (UMD) report:

We observed the field of the LAT GRB 180914A (Bissaldi, et al., GCN
23225) with the Reionization and Transients Infrared Camera (RATIR;
www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio
Astronomico Nacional on Sierra San Pedro Martir from 2018/09 15.29 to
2018/09 15.50 UTC (18.54 to 23.57 hours after the Fermi trigger),
obtaining a total of 3.00 hours exposure in the r and i bands and
1.24 hours exposure in the Z, Y, J, and H bands.

For a source within the Swift-XRT error circle (D'Elia, et al.,
GCN 23229), in comparison with the SDSS DR9 and 2MASS catalogs, we
obtain the following upper limits (3-sigma):

   r    > 24.2
   i    > 24.1
   Z    > 22.7
   Y    > 22.5
   J    > 22.0
   H    > 21.6

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 Astronomico Nacional in San Pedro
Martir.