TITLE:   GCN CIRCULAR
NUMBER:  9240
SUBJECT: GRB 090424 : TAOS optical detection
DATE:    09/04/25 01:27:48 GMT
FROM:    Kuiyun Huang at ASIAA  <ljhuang@asiaa.sinica.edu.tw>

GRB 090424 : TAOS optical detection

Y. Urata, Z.W. Zhang, C.Y. Wen, K.Y. Huang, S.Y. Wang and the TAOS
team

Three 50cm TAOS telescopes, located at Lulin observatory, Taiwan,
started to observe GRB 090424 field (Cannizzo et al.; GCN 9223) at 94s
after the trigger. The optical afterglow (Yuan et al., GCN 9224; Xin
et al. GCN 9225) was clearly detected in images taken by TAOSA (25s
exposure), TAOSB (5s exposure), and TAOSD (1s exposure). Brightness of
the afterglow is about R~13.08 at 94s post the burst. Our R-band
magnitude were calibrated with USNOB red stars.

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