TITLE: GCN CIRCULAR NUMBER: 15812 SUBJECT: GRB 140209A, Swift-BAT refined analysis DATE: 14/02/09 19:27:41 GMT FROM: Hans Krimm at NASA-GSFC D. M. Palmer (LANL), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), S. B. Cenko (GSFC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/UMBC), C. B. Markwardt (GSFC), T. Sakamoto (AGU), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team): Using the data set from T-61 to T+243 sec from the recent telemetry downlink, we report further analysis of BAT GRB 140209A (trigger #586071) (Cenko, et al., GCN Circ. 15808). The BAT ground-calculated position is RA, Dec = 81.328, 32.488 deg which is RA(J2000) = 05h 25m 18.7s Dec(J2000) = +32d 29' 17.3" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 38%. The mask-weighted light curve shows an initial weak pulse from T+0 to T+0.5 sec, followed by the main pulse from T+1.5 to T+3.5 sec, with a FRED-like profile with some superimposed structure. This is followed by some low-level extended emission out to ~T+50 sec. T90 (15-350 keV) is 21.3 +- 8.0 sec (estimated error including systematics). The time-averaged spectrum from T+0.15 to T+29.22 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.44 +- 0.06. The fluence in the 15-150 keV band is 4.1 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+1.69 sec in the 15-150 keV band is 38.1 +- 1.1 ph/cm2/sec. All the quoted errors are at the 90% confidence level. It is possible that this burst falls in the category of short burst with extended emission. A lag analysis is underway that will be reported in a subsequent circular. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/586071/BA/