//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11922 SUBJECT: GRB 110412A: Swift detection of a burst DATE: 11/04/12 07:44:19 GMT FROM: Jonathan Gelbord at PSU/Swift J. M. Gelbord (PSU), V. D'Elia (ASDC), P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC), V. Mangano (INAF-IASFPA), C. B. Markwardt (NASA/GSFC), J. P. Osborne (U Leicester), C. Pagani (U Leicester), K. L. Page (U Leicester), M. H. Siegel (PSU) and M. Stamatikos (OSU/NASA/GSFC) report on behalf of the Swift Team: At 07:33:21 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 110412A (trigger=451191). Swift did not slew to the location because the position is in an observing constraint. The BAT on-board calculated location is RA, Dec 133.492, +13.517 which is RA(J2000) = 08h 53m 58s Dec(J2000) = +13d 30' 60" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single-peaked structure with a duration of about 30 sec. The peak count rate was ~600 counts/sec (15-350 keV), at ~20 sec after the trigger. Due to a Moon observing constraint, Swift cannot slew to the BAT position until 15:08 UT on 2011 April 14. There will thus be no XRT or UVOT data for this trigger before this time. Burst Advocate for this burst is J. M. Gelbord (jgelbord AT astro.psu.edu). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11926 SUBJECT: GRB 110412A: Fermi GBM observation DATE: 11/04/12 13:16:29 GMT FROM: Arne Rau at MPE Arne Rau (MPE) reports on behalf of the Fermi GBM Team: "At 07:33:35.71 UT on 12 April 2011, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 110412A (trigger 07:33:35.71 / 110412315) which was also detected by the Swift/BAT (Gelbord et al. 2011, GCN 11922). The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight is 53 degrees. The GBM light curve shows a single peak with a duration (T90) of about 16 s (50-300 keV). The time-averaged spectrum from T0-1.5 s to T0+18.9 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.7 +/- 0.1 and the cutoff energy, parameterized as Epeak, is 87 +/- 5 keV The event fluence (10-1000 keV) in this time interval is (2.2 +/- 0.1)E-06 erg/cm^2. The 1.024-sec peak photon flux measured starting from T0+5.8 s in the 10-1000 keV band is 2.7 +/- 0.2 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11929 SUBJECT: GRB 110412A: Swift-BAT refined analysis DATE: 11/04/12 20:13:44 GMT FROM: Scott Barthelmy at NASA/GSFC W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), J. M. Gelbord (PSU), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team): Using the data set from T-60 to T+243 sec from recent telemetry downlinks, we report further analysis of BAT GRB 110412A (trigger #451191) (Gelbord, et al., GCN Circ. 11922). The BAT ground-calculated position is RA, Dec = 133.491, 13.488 deg, which is RA(J2000) = 08h 53m 57.9s Dec(J2000) = +13d 29' 15.4" with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment). The partial coding was 18%. The mask-weighted light curve shows a FRED-like pulse starting at ~T+10 sec, peaking at ~T+20 sec, and ending at ~T+45 sec. T90 (15-350 keV) is 23.4 +- 4.1 sec (estimated error including systematics). The time-averaged spectrum from T+13.7 to T+40.4 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.54 +- 0.14. The fluence in the 15-150 keV band is 1.8 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+18.96 sec in the 15-150 keV band is 2.0 +- 0.4 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/451191/BA/