TITLE: GCN CIRCULAR NUMBER: 5905 SUBJECT: GRB 061210, Swift-BAT refined analysis of the SHB DATE: 06/12/10 16:39:14 GMT FROM: Scott Barthelmy at NASA/GSFC D. Palmer (LANL), L. Barbier (GSFC), S. D. Barthelmy (GSFC), J. K. Cannizzo (GSFC/UMBC), J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), D. Hullinger (BYU-Idaho), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), A. Parsons (GSFC), T. Sakamoto (GSFC/ORAU), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC) on behalf of the Swift-BAT team: Using the data set from T-239 to T+478 sec from the recent telemetry downlink, we report further analysis of BAT GRB 061210 (trigger #243690) (Cannizzo, et al., GCN Circ. 5904). The BAT ground-calculated position is RA, Dec = 144.521, 15.613 deg which is RA(J2000) = 09h 38m 05.1s Dec(J2000) = 15d 36' 46.3" with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 30%. The mask-weighted lightcurve has a hard FRED-like spike lasting a total of ~192 msec followed by much weaker, softer emssion lasting out to ~T+90 sec. T90 (15-350 keV) is 85 +- 5 sec (estimated error including systematics). The event-by-event data shows the FRED-like peak is resolved to 3 somewhat overlapping spikes within 60 msec. The time-averaged spectrum from T+0.2 to T+89.6 is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.55 +- 0.28. The fluence in the 15-150 keV band is 1.1 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T-0.01 sec in the 15-150 keV band is 5.3 +- 0.5 ph/cm2/sec. The spectrum of the first spike alone (T+0.212 to T+0.760 sec) is also fit by a simple power law model. The power law index of the initial spike is 0.79 +- 0.15. The fluence in the 15-150 keV band is 3.0 +- 0.3 x 10^-7 erg/cm2. All the quoted errors are at the 90% confidence level.