[vsnet-grb-info 14578] GRB 140226A/iPTF14yb: RATIR Optical and NIR Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15892
SUBJECT: GRB 140226A/iPTF14yb: RATIR Optical and NIR Observations
DATE:    14/02/28 15:47:46 GMT
FROM:    Antonino Cucchiara at NASA/GSFC  <antonino.cucchiara at nasa.gov>

Antonino Cucchiara (ORAU/GSFC),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), 
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 again the field of the GRB-like transient iPTF14yb (Cenko et al., GCN 15883, 
Beardmore et al., GCN 15884, 15891) 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 2014/02 28.34 to 2014/02 28.53 UTC (roughly 46 
to 50 hours after the reported time of discovery), obtaining a total of 2.63 hours exposure 
in the r and i bands and 1.12 hours exposure in the Z, Y, J, and H bands.

For the source within the Cenko et al. (GCN 15883) error circle, in comparison with the 
SDSS DR9 and 2MASS, we obtain the following detections and upper limits:

  r	23.28 +/- 0.32   
  i	22.51 +/- 0.20   
  Z	> 22.11   
  J	> 21.73   

The detections are at the 2-sigma level and the upper limits at the 3-sigma level.
These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.

Our photometry indicates that the transient is still fading in r band with a similar
decay index (within the systematic errors) as reported by Cucchiara et al. (GCN 
15886).

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