TITLE: GCN CIRCULAR NUMBER: 7584 SUBJECT: GRB 080411: Swift detection of a bright burst DATE: 08/04/11 21:47:27 GMT FROM: Scott Barthelmy at NASA/GSFC F. E. Marshall (NASA/GSFC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester), D. N. Burrows (PSU), N. Gehrels (NASA/GSFC), O. Godet (U Leicester), S. T. Holland (CRESST/USRA/GSFC), H. A. Krimm (CRESST/GSFC/USRA), C. B. Markwardt (CRESST/GSFC/UMD), K. M. McLean (GSFC/UMD), C. Pagani (PSU), K. L. Page (U Leicester), D. M. Palmer (LANL), M. Stamatikos (NASA/ORAU), R. L. C. Starling (U Leicester), T. N. Ukwatta (GSFC/GWU), L. Vetere (PSU) and P. A. Ward (MSSL-UCL) report on behalf of the Swift Team: At 21:15:32 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 080411 (trigger=309010). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 38.018, -71.342 which is RA(J2000) = 02h 32m 04s Dec(J2000) = -71d 20' 30" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The TDRSS BAT lightcurve shows the burst starting with a fast rise from background to ~13,000 counts/sec in approximately 0.5 sec. There are several peaks after that with the fourth peak (T+19 sec) at 75,000 cnts/sec. There are several more peaks after that lasting out to at least T+70 sec. The XRT began observing the source at 21:16:42 UT (71 s after the trigger). The XRT centroided on something very bright. We have lost most of our prompt diagnostic messages because the spacecraft switched from TDRSS telemetry to Malindi telemetry shortly after the burst, and our prompt image does not include the source. However, the information within the header indicates that the source is located near the center of the XRT field of view, and is therefore probably real. If real, the position is GRB_RA: 37.9860d {+02h 31m 56.6s} (J2000), GRB_DEC: -71.3021d {-71d 18' 07.5"} (J2000), with an uncertainty of 4.3 arcseconds (90% confidence radius), and the flux during this image was approximately 4.4e-7 cgs (~ 10 Crabs) in the 0.1 s image. The XRT position is 148 arcseconds from the BAT position. No UVOT data for this burst are currently available. Burst Advocate for this burst is F. E. Marshall (marshall AT milkyway.gsfc.nasa.gov). 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.)