TITLE: GCN CIRCULAR NUMBER: 11436 SUBJECT: GRB 101129A SHB found by IPN and in ground analysis of BAT data DATE: 10/12/03 02:36:37 GMT FROM: Jay R. Cummings at NASA/GSFC/Swift J. R. Cummings (GSFC/UMBC/CRESST), D. M. Palmer (LANL), S. D. Barthelmy (GSFC), and T. Sakamoto (GSFC/UMBC/CRESST) on behalf of the BAT team, Valentin Pal'shin (Ioffe Inst) and K. Hurley (UCB) on behalf of the IPN, V. Connaughton, M.S. Briggs, and C.A. Meegan on behalf of the Fermi GBM team, A. von Kienlin, G. Lichti, and A. Rau, on behalf of the INTEGRAL SPI-ACS GRB team, A. P. Beardmore (U Leicester) and J. A. Kennea (PSU) on behalf of the Swift-XRT team, K. Yamaoka, M. Ohno, Y. Hanabata, Y. Fukazawa, T. Takahashi, M. Tashiro, Y. Terada, T. Murakami, and K. Makishima, on behalf of the Suzaku WAM team, J. Goldsten, on behalf of the MESSENGER NS GRB team: At 15:39:31 UTC, Swift-BAT detected a rate increase due to GRB 101129A (BAT trigger #439471. Only a sub-threshold image source was found onboard. This event corresponds to Fermi GBM trigger #312737973. The IPN was alerted. In ground analysis, the source was detected with slightly greater confidence at RA, Dec 155.921, -17.645 which is: RA (J2000) 10h 23m 41s Dec (J2000) -17d 38m 42s with an estimated uncertainty radius of 3 arcmin (90% containment). Correlation of Swift-BAT counting rates and SPI-ACS counting rates, and SPI-ACS with Messenger yielded intersecting annuli consistent with this position. The burst was also detected by Suzaku-WAM. As seen in BAT, the burst consisted of a single pulse with a T90 of about 0.35 +- 0.05 sec. The burst was faint and short. The low-number statistics in BAT make a fit to the spectrum very uncertain. The photon index was approximately 0.8 +- 0.5. The fluence was approximately (9 +- 5) x 10^-08 ergs/cm^2. A Swift TOO observation was executed at 11 hours after the burst. The location of the burst was observed by the Swift-XRT and Swift-UVOT for a total of about 1400 seconds. No afterglow was detected. No further observations are planned.