TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4492 SUBJECT: GRB 060111B: Refined analysis of the Swift-BAT burst DATE: 06/01/12 03:10:05 GMT FROM: Scott Barthelmy at NASA/GSFC J. Tueller (GSFC), L. Barbier (GSFC), S. Barthelmy (GSFC), J. Cannizzo (GSFC-UMBC), L. Cominsky (Sonoma State U.), J. Cummings (GSFC/NRC), E. Fenimore (LANL), N. Gehrels (GSFC), D. Hullinger (GSFC/UMD), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/NRC), G. Sato (ISAS) on behalf of the Swift-BAT team: Using the partial data set (T-60.2 to T+122.9 sec) from the recent telemetry downlink, we report further analysis of BAT GRB 060111 (trigger #176918) (Perri, et al., GCN 4487). The BAT ground-calculated position is RA,Dec = 286.460,+70.382 deg {19h 5m 50.4s,+70d 22' 54.0"} (J2000) +- 1.6 arcmin, (radius, sys+stat, 90% containment). The partial coding was 29%. The mast-weighted lightcurve shows two peaks. The first one starts at T-4 sec, peaks at T+1, and extends out to T+28 sec. The second, smaller peak starts at T+53, peaks at T+55, and is over by T+62 sec. T90 (15-350 keV) is 59 +- 1) sec (estimated error including systematics). The power law index of the time-averaged spectrum (T-2 to T+63 sec) is 1.04 +- 0.17. The fluence in the 15-150 keV band is (1.6 +- 0.1) x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+0.36 sec in the 15-150 keV band is 1.4 +- 0.3 ph/cm2/sec. All the quoted errors are at the 90% confidence level.