[vsnet-grb-info 14676] GRB 140318A: RATIR Optical and NIR Detections

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15990
SUBJECT: GRB 140318A: RATIR Optical and NIR Detections
DATE:    14/03/18 08:32:11 GMT
FROM:    Owen Littlejohns at Az State U  <olittlej at asu.edu>

Owen Littlejohns (ASU), 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), 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 140318A (Cenko, et al., GCN 15986) 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 2014/03 18.15 to 2014/03 18.31
UTC (3.36 to 7.40 hours after the BAT trigger) obtaining a total of 0.99
hours exposure in the r and i bands and 0.60 hours exposure in the Z, Y,
J, and H bands.

We detect the previously reported optical counterpart (Schulze, et al. GCN
15987). In comparison with the SDSS DR9 and 2MASS, we obtain the following
detections:

  r     21.88 +/- 0.33
  i     21.37 +/- 0.18
  Z     20.67 +/- 0.20
  Y     20.76 +/- 0.29
  J     20.60 +/- 0.21
  H     20.29 +/- 0.19

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB. In comparison to the observations
of Schulze, et al. (GCN 15987) the measured r-band magnitude is consistent
with a power-law decay with a temporal index alpha = -1.0.

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