[vsnet-grb-info 16332] GRB 150323A: RATIR Optical Afterglow Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17613
SUBJECT: GRB 150323A: RATIR Optical Afterglow Observations
DATE:    15/03/23 04:09:49 GMT
FROM:    Nat Butler at Az State U  <natbutler at asu.edu>

Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William
H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), 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), and
Harvey Moseley (GSFC) report:

We observed the field of GRB 150323A (Amaral-Rogers, et al., GCN 17611)
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 2015/03 23.12 to 2015/03 23.16 UTC
(9.6 to 58.8 minutes after the BAT trigger), obtaining a total of 42.6
minutes exposure in the r, i, and z bands.

For the source on the edge of the Swift-XRT error circle (Cenko et al., GCN
17612), in comparison with the SDSS DR9, we obtain the following
measurements and upper-limit (3-sigma):

  r = 21.16 +/- 0.11
  i = 20.39 +/- 0.05
  z > 19.30

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.  We note that this source appears
to be fading during our observation.

We thank the staff of the Observatorio Astronómico Nacional in San
Pedro Mártir.