NASA Swift: GRB 060526: ROTSE-III Observations of Optical Counterpart

TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 5166
SUBJECT: GRB 060526: ROTSE-III Observations of Optical Counterpart
DATE: 06/05/26 21:36:39 GMT
FROM: Eli Rykoff at U of Michigan/ROTSE erykoff@umich.edu

E.S. Rykoff (U Mich), S.A. Yost (U Mich), H. Swan (U Mich), W. Rujopakarn (U Mich), report on behalf of the ROTSE collaboration:

ROTSE-IIIc, located at the H.E.S.S. site at Mt. Gamsberg, Namibia, responded to GRB 060526 (Swift trigger 211957, GCN 5162). The first image was at 17:15:11.1 UT, 2801.1 s after the burst. The unfiltered images are calibrated relative to USNO A2.0. We detect a 17.5th magnitude, fading source with coordinates:

15:31:18.3 +00:17:03.7 (J2000)

This is consistent with the Swift/UVOT position reported in GCN 5162.

The afterglow did not fade significantly between 2800s and ~6000s post-burst, when it was at ~ 17.5 mag. At 6000s the lightcurve had a break, and started decaying as a smooth power-law with index ~-1. At 13000 s post-burst, the afterglow is at 18.4+/-0.05 mag. Observations are continuing.

A jpeg image is available at http://www.rotse.net/images/gsb211957_3c091-100_key.jpg