TITLE:   GCN CIRCULAR
NUMBER:  7610
SUBJECT: Swift-BAT spectral lag analysis of GRB 080413B
DATE:    08/04/13 19:59:34 GMT
FROM:    Michael Stamatikos at GSFC  <michael.stamatikos-1@nasa.gov>

T. Sakamoto (GSFC/UMBC), T. Ukwatta (GWU), M. Stamatikos (GSFC/ORAU), S. D.
Barthelmy (GSFC), N. Gehrels (GSFC),

We further report on additional spectral lag analysis regarding the possible
short duration burst classification of GRB 080413B (Stamatikos et al. GCN
Circ. 7598). We now believe GRB 080413B to be a long GRB based upon the
following BAT prompt emission properties:

1) The spectral lag in 25-50 to 100-350 keV bands and 15-25 to 50-100 keV
bands are 0.238 +- 0.016 sec and 0.136 +- 0.008 sec for 4 ms binning.
Therefore, GRB 080413B shows a significant lag.

2) The T90 of the spike is 8.0 +- 1.0 sec based on the mask-weighted light
curve (Barthelmy et al., GCN 7606), which is well within the long duration
GRB population (Sakamoto et al. ApJS, 175, 179).