[vsnet-grb-info 15350] GRB 140729A: iPTF optical upper limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16640
SUBJECT: GRB 140729A: iPTF optical upper limit
DATE:    14/07/30 04:32:40 GMT
FROM:    Leo Singer at CIT/PTF  <lsinger at caltech.edu>

L. P. Singer (Caltech), S. B. Cenko (NASA/GSFC), and M. M. Kasliwal
(Carnegie Observatories/Princeton) report on behalf of the
intermediate Palomar Transient Factory (iPTF) collaboration:

We searched for optical counterparts of GRB 140729A (Arimoto, GCN 16633;
Bissaldi, GCN 16635; Stanbro, GCN 16636) using the Palomar 48-inch
Oschin telescope (P48). Based on the final Fermi GBM localization
with a 1-sigma statistical radius of 1.57 deg, we imaged 10 fields
covering an area of 73 deg2. These fields also contained all of the
Fermi LAT error circle and its intersection with the IPN annulus
(Svinkin, GCN 16637).

In our observations on 2014-07-29 from 04:05:50 to 04:51:48 UT (3.48
to 4.5 hours after the burst), we find no plausible optical afterglow
candidates within the LAT error circle, to a limiting magnitude of
R=20.6.

The diagram http://www.its.caltech.edu/~lsinger/iptf/Fermi428287016.pdf
shows the locations of our ten P48 fields in relation to the Fermi
GBM 1- and 2-sigma statistical+systematic contours as well as the LAT
error circle and the IPN annulus.