Very early multi-color observations of the plateau phase of GRB 041006   afterglow
  Observations of the optical afterglow of GRB 041006 with the Kiso Observatory 1.05 m Schmidt telescope, the Lulin Observatory 1.0 m telescope and the Xinglong Observatory 0.6 m telescope. Three-bands (B, V and R) of photometric data points were obtained on 2004 October 6, 0.025-0.329 days after the burst. These very early multi band light curves imply the existence of a color dependent plateau phase. The B-band light curve shows a clear plateau at around 0.03 days after the burst. The R band light curve shows the hint of a plateau, or a possible slope change, at around 0.1 days after the burst. The overall behavior of these multi-band light curves may be interpreted in terms of the sum of two separate components, one showing a monotonic decay the other exhibiting a rising and a falling phase, as described by the standard afterglow model. 
Y. Urata, K.Y. Huang, Y.L. Qiu, J. Hu, P.H. Kuo, T. Tamagawa, W.H. Ip,   D. Kinoshita, H. Fukushi, M. Isogai, T. Miyata, Y. ...