TITLE:   GCN CIRCULAR
NUMBER:  15772
SUBJECT: GRB140129A: RAPTOR Observations of the Early Afterglow
DATE:    14/01/30 00:45:09 GMT
FROM:    James Wren at LANL  <jwren@nis.lanl.gov>

J. Wren, W.T. Vestrand, P. Wozniak, and H. Davis,
of Los Alamos National Laboratory report:

The RAPTOR network of robotic optical telescopes made follow-up observations
of Swift trigger 585128 (Melandri, et al., GCN 15760).  Our narrow-field
instruments in Los Alamos, NM,  began imaging at 03:25:05.19 UT, 65.7 seconds
after the BAT trigger time.  Our RAPTOR-T robotic telescope measured the
counterpart simultaneously in SDSS g', r', i', and z' bands through the first
1000 seconds after the BAT trigger.  In r' band, the counterpart is at
magnitude 14.72 +- 0.04 at T+68.22 seconds.  By T+217.21, the source had
faded to r' magnitude 16.24 +- 0.07, consistent with the P60 observations
(Perley, et al., GCN 15761).  The counterpart fades monotonically during the
observation interval.  Our images were calibrated to the SDSS DR9 catalog.