- Only part of the event data are used in order to have a more reasonable estimation of burst durations. There is a ~ 3 sigma bump around ~T+630 s, which causes a very long T90. However, due to no related XRT flares are seen around that time, the BAT team determined that this bump is likely to be noise fluctuation. Therefore, Only data before T+650 is used in the analyais to produce a more reasonable burst duration.