TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3814 SUBJECT: GRB050815: Refined analysis of the Swift-BAT burst DATE: 05/08/15 22:13:37 GMT FROM: Scott Barthelmy at NASA/GSFC D. Hullinger (GSFC/UMD), M. Ajello (MPE), L. Barbier (GSFC), S. Barthelmy (GSFC), J. Cummings (GSFC/NRC), E. Fenimore (LANL), R. Fink (GSFC), N. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/NRC), G. Sato (ISAS), J. Tueller (GSFC) on behalf of the Swift-BAT team: Using the full data set from the recent telemetry downlink, we report further analysis of Swift-BAT GRB 050815 (trigger #150532) (Fox, et al., GCN 3811). The ground-analysis position is RA,Dec 293.579,+9.145 (J2000) with an uncertainty of 2 arcmin (radius, 90%, stat+sys). This is 59 arcsec from the XRT refined position (Morris et al., GCN 3812). The light curve shows an increase in emission starting at T-2 sec with a peak at ~T+1 sec and the burst is over by T+4 sec. T90 is 2.8 +/-1 sec. Fitting a simple power law over the interval from T-0.7 to T+2.4 sec, the photon index is 1.8 +/- 0.2 with a fluence of 1.5 +/- 0.4 x 10^-7 erg/cm^2 in the 15-350 keV band (90% c.l.). The peak flux in a 1-sec wide window starting at T-0.1 seconds is 0.66 +/- 0.14 ph/cm^2/sec (15-350 keV). Based on the duration of >2 sec and the soft spectrum, it does not appear that this burst is in the short-hard category.