GCN Circular 16123
NPM Kuin (MSSL-UCL), and F. E. Marshall (NASA/GSFC) report on behalf of the Swift Team: UVOT started observing GRB 140419A starting 96 seconds after the BAT trigger. The initial finding chart exposures with the White and U filter show a fading source in the white filter which we identify with the afterglow: The estimated magnitudes are as follows: filter starttime endtime magnitude error wh 96 246 16.01 0.06 u 308 558 >19.6 wh 862 1012 17.96 0.09. The source is not seen in the u filter, which suggests a redshift larger then 2.8. No correction has been made for the expected extinction corresponding to E(B-V) of 0.03.