[vsnet-grb-info 21114] GRB 180905A: RATIR Optical and NIR Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  23212
SUBJECT: GRB 180905A: RATIR Optical and NIR Observations 
DATE:    18/09/06 13:30:04 GMT
FROM:    Alan M. Watson at Instituto de Astronomia UNAM  <alan at astro.unam.mx>

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 (U. Wash.), and Vicki
Toy (UMD) report:

We observed the field of GRB 180905A (D'Elia et al., GCN Circ. 23201)
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 2018/09 6.42 to
2018/09 6.51 UTC (20.07 to 22.23 hours after the BAT trigger), obtaining
a total of 1.17 hours exposure in the r and i bands and 0.57 hours
exposure in the Z, Y, J, and H bands.

For a source within the Swift-XRT enhanced error circle (Beardmore et
al., GCN Circ. 23207), in comparison with the USNO-B1 and 2MASS
catalogs, we obtain the following upper limits (3-sigma):

  r	> 23.26
  i	> 23.10
  Z	> 22.21
  Y	> 22.06
  J	> 21.60
  H	> 21.25

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.