TITLE:   GCN CIRCULAR
NUMBER:  9224
SUBJECT: GRB 090424: ROTSE-III Confimation of Optical Counterpart
DATE:    09/04/24 14:35:53 GMT
FROM:    Fang Yuan at ROTSE  <yuanfang@umich.edu>

F. Yuan (U Mich), report on behalf of the ROTSE collaboration:

ROTSE-IIIa, located at Siding Spring Observatory, Australia, responded  
to GRB 090424 (Swift trigger 350311;Cannizzo et al, GCN 9223). The  
first image started at 14:18:41.4 UT, ~6 min after the burst. The  
unfiltered images are calibrated relative to USNO A2.0. We detect a  
fading source at the position consistent with the UVOT OT, at the  
following magnitude:


start UT    	mag     mlim(of image)
----------------------------------
14:18:41.4     15.5     17.2


This source is not visible in DSS (second epoch), 2MASS or the  
MPChecker database.

A jpeg image is available at http://www.rotse.net/images/gsb350311_3a001-010_key.jpg 
  Note that the object marked 12 is the candidate in question.

Continuing observations are in progress.