[vsnet-grb-info 16892] GRB 150819A: RATIR Optical Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  18173
SUBJECT: GRB 150819A: RATIR Optical Observations
DATE:    15/08/19 14:08:37 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 (UCB), J. Xavier 
Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), 
Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), 
José A. de Diego (UNAM), Leonid Georgiev (UNAM), Jesús González (UNAM), 
Carlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC), Harvey Moseley (GSFC), 
John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD) report:

We observed the field of GRB 150819A (Ukwatta et al., GCN 18163) 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 2015/08 19.33 to 2015/08 19.48 UTC (7.08 to 
10.60 hours after the BAT trigger), obtaining a total of 2.80 hours 
exposure in the r and i bands.

For a source within the enhanced Swift-XRT error circle (Evans et al., GCN 
18165), in comparison with the USNO-B1 and 2MASS catalogs, we obtain the 
following upper limits (3-sigma):

   r	> 23.60
   i	> 23.91

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.