[vsnet-grb-info 21208] GRB 181003A: RATIR Optical and NIR Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  23307
SUBJECT: GRB 181003A: RATIR Optical and NIR Observations 
DATE:    18/10/04 19:27:17 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 181003A (Beardmore et al., GCN Circ. 23295)
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 2018/10 4.32 to
2018/10 4.46 UTC (26.59 to 29.89 hours after the BAT trigger), obtaining
a total of 1.41 hours exposure in the r and i bands and 0.58 hours
exposure in the Z, Y, J, and H bands.

For a source within the Swift-XRT error circle (Tohuvavohu et al., GCN
Circ. 23305), in comparison with the USNO-B1 and 2MASS catalogs, we
obtain the following 3-sigma upper limits:

  r	> 23.40
  i	> 23.15
  Z	> 22.01
  Y	> 21.53
  J	> 21.19
  H	> 20.73

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.