TITLE: GCN CIRCULAR NUMBER: 9225 SUBJECT: GRB 090424: TNT optical observations DATE: 09/04/24 15:21:45 GMT FROM: W.K. Zheng at NAOC L.P. Xin, W.K. Zheng, Y.L. Qiu, J.Y. Wei, j. Wang, J.S. Deng, Y. Urata and J.Y. Hu on behalf of EAFON report: TNT quickly responsed to the GRB 090424 (Swift trigger 350311; Cannizzo et al. GCN 9223) in automatical mode, the first images was taken start 14:13:36, 87s after the burst. The optical afterglow (Cannizzo et al. GCN 9223; Yuan GCN 9224) was clearly detected in our early white and R bands images, after preliminary reduction, we estimated the afterglow have faded about 3.5 mag from ~100s to ~1000s after the burst. Observation is still under going. This message may be cited.