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 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.