TITLE: GCN CIRCULAR NUMBER: 14373 SUBJECT: GRB 130408A, Swift-BAT refined analysis DATE: 13/04/09 23:45:37 GMT FROM: Craig Markwardt at NASA/GSFC W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/GSFC/ORAU), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team): Using the data set from T-240 to T+960 sec from the recent telemetry downlink, we report further analysis of BAT GRB 130408A (trigger #553132) (Lien, et al., GCN Circ. 14361). The BAT ground-calculated position is RA, Dec = 134.398, -32.363 deg which is RA(J2000) = 08h 57m 35.5s Dec(J2000) = -32d 21' 45.9" with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 6%. T90 (15-350 keV) is 28 +- 13 sec (estimated error including systematics). The mask weighted light curve has a main FRED-like component with a rise time of about 2 sec and decline of 5 sec, peaking at time T+1 sec, followed by a smaller peak at T+12 sec. There is possible low-level emission out to about T+33 sec. The time-averaged spectrum from T-0.1 to T+33.5 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.28 +- 0.26. The fluence in the 15-150 keV band is 2.3 +- 0.4 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+1.12 sec in the 15-150 keV band is 4.9 +- 1.0 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/553132/BA/