//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10212 SUBJECT: GRB 091130: Swift detection of a possible burst DATE: 09/11/30 16:33:57 GMT FROM: David Palmer at LANL H. A. Krimm (CRESST/GSFC/USRA), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester), D. N. Burrows (PSU), S. Campana (INAF-OAB), J. R. Cummings (NASA/UMBC), P.A. Curran (MSSL-UCL), V. D'Elia (ASDC), P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC), C. Guidorzi (U Ferrara), S. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU), J. A. Kennea (PSU), N. P. M. Kuin (MSSL), V. Mangano (INAF-IASFPA), J. Mao (INAF-OAB), F. E. Marshall (NASA/GSFC), P. T. O'Brien (U Leicester), C. Pagani (PSU), K. L. Page (U Leicester), D. M. Palmer (LANL), J. L. Racusin (NASA/GSFC), P. Romano (INAF-IASFPA), T. Sakamoto (NASA/UMBC), B. Sbarufatti (INAF-IASFPA), M. H. Siegel (PSU), M. Stamatikos (OSU/NASA/GSFC), E. Troja (NASA/GSFC/ORAU) and T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift Team: At 16:08:10 UT, the Swift Burst Alert Telescope (BAT) triggered and located possible GRB 091130 (trigger=377436). Swift did not immediately slew to this burst due to the Earth limb constraint. The BAT on-board calculated location is RA, Dec 161.881, +11.626 which is RA(J2000) = 10h 47m 32s Dec(J2000) = +11d 37' 32" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). As is typical for an image trigger, the light curve shows no obvious burst-like structure. Due to an observing constraint, Swift will not slew until T0+49.3 minutes. There will be no XRT or UVOT data until this time. Without observations by XRT or UVOT, without a clear light curve, and with only a marginal (7.13 sigma) image, we cannot confirm at this time that this is a true GRB. This uncertainty will be resolved if the XRT detects a source during its observation, or when the full BAT data is downlinked via Malindi. Burst Advocate for this burst is H. A. Krimm (krimm 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.) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10213 SUBJECT: GRB 091130: MASTER observations DATE: 09/11/30 17:50:28 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs S.Sergienko, V.Yurkov Blagoveschensk Educational State University, Blagoveschensk E. Gorbovskoy, D. Zimnukhov, V. Lipunov, V.Kornilov, A.Belinski, D.Kuvshinov, N.Shatskiy, N.Tyurina, P.Balanutsa, V.V.Chazov, A.Kuznetsov Sternberg Astronomical Institute, Moscow State University A. Tlatov, A.V. Parkhomenko, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory V.Krushinski, I.Zalognikh, T.Kopytova, A. Popov Ural State University, Kourovka S.Yazev, K.Ivanov, N.M.Budnev, E.Konstantinov, V.Lenok Irkutsk State University MASTER robotic telescope (MASTER-Net: http://observ.pereplet.ru, D= 200 mm, FOV= 7 square degrees, 16 Mpx Apogee CCD, testing mode) located at Blagoveschensk was responted to the GRB 091130 (Krimm et al., GCN 10212) 23 sec after Notice time and 7 min 22 s after the GRB time. The first images are saturated due to the Moon light and cloudes. After exposition correction we took several dozens succesfull images with limit ~14.5 mag. Time T_start-T_GRB ExpTime m_lim 16:43:56 35:45 60s 14.5 16:43:56 35:45-47:03 10x60s 16 We do not see OT brighter 14 mag in BAT error box. The reduction is continued. The message may be cited. The summ of the images is available at http://observ.pereplet.ru/images/GRB091130/grb091130.jpeg. We note that MASTER-Amur-Blagoveschensk are in testing mode now. mailto: lipunov@sai.msu.ru //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10217 SUBJECT: Swift trigger 377436 (possible GRB 091130A) is not a burst DATE: 09/11/30 22:38:10 GMT FROM: Hans Krimm at NASA-GSFC H. A. Krimm (CRESST/GSFC/USRA), S. D. Barthelmy (GSFC), A. P. Beardmore (U Leicester), J. R. Cummings (CRESST/GSFC/UMBC), E. Hoversten (PSU), on behalf of the Swift team. Using the Swift/BAT data set from T-60 to T+236 sec and the XRT data set beginning at T+58 minutes from recent telemetry downlinks, we report that BAT trigger 356516 (reported as possible GRB 091130A, Krimm et al, Circ 10212) is probably not a GRB. We base this conclusion on the low significance in the BAT and the lack of a counterpart in the XRT. However, we can not rule out that this is an astrophysical event which was extended in duration in the BAT (the original trigger was a 400-sec integration), but rapidly fading prior to the XRT observations. The BAT image shows a 3.5 sigma bump and the mask-weighted light curve shows an integrated 5-sigma positive excess out to T+236 sec. If the source is real, it is at RA, Dec = 161.854, +11.580 deg with an uncertainty of 4.5 arcmin, (radius, sys+stat, 90% containment). The partial coding is 97%. In 2.57 ks of Swift-XRT photon counting mode data beginning at T+58 minutes, we do not detect any X-ray source in the BAT error circle to a 3 sigma upper limit count rate of 8.0e-3 count/s. This corresponds to a 0.3-10 keV observed flux limit of 3.1e-13 erg cm-2 s-1, assuming a typical counts-to-flux conversion factor of 3.9e-11 erg cm-2 count-1. UVOT took a finding chart exposure of 150 seconds with the White filter starting 3592 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x 2.7' sub-image covers 25% of the BAT error circle. The typical 3-sigma upper limit has been about 19.6 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the BAT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.03. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10221 SUBJECT: GRB 091130B: Swift-BAT refined analysis DATE: 09/12/01 05:44:50 GMT FROM: Jay R. Cummings at NASA/GSFC/Swift T. N. Ukwatta (GWU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), A. M. Parsons (GSFC), J. L. Racusin (NASA/GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC) (i.e. the Swift-BAT team): Using the data set from T-60 to T+243 sec from the recent telemetry downlink, we report further analysis of BAT GRB 091130 (trigger #377487) (Racusin, et al., GCN Circ. 10214). The BAT ground-calculated position is RA, Dec = 203.149, 34.086 deg which is RA(J2000) = 13h 32m 35.8s Dec(J2000) = +34d 05' 11.0" with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 77%. The mask-weighted light curve shows several broad, irregular, overlapping peaks starting at T-25 sec, peaking at T0 and ending about T+120 sec. T90 (15-350 keV) is 112.5 +- 17.1 sec (estimated error including systematics). The time-averaged spectrum from T-4.7 to T+127.4 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.15 +- 0.15. The fluence in the 15-150 keV band is 1.3 +- 0.1 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T-0.06 sec in the 15-150 keV band is 1.1 +- 0.2 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/377487/BA/ [GCN OPS NOTE(01dec09): Changed "091130" to "091130B".] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10227 SUBJECT: GRB 091130A: Xinglong TNT upper limit DATE: 09/12/02 06:54:04 GMT FROM: L.P. Xin at NAOC Y.L. Qiu, X.F. Wang, C. Wu, L.P. Xin, J. Wang, J.Y. Wei, W. K. Zheng, J. S. Deng, and J. Y. Hu on behalf of EAFON report: We observed the optical afterglow of GRB 091130A (Krimm et al. GCN 10212) with Xinglong TNT telescope from Nov. 30th, 18:25:41 (UT), 2.27 hours after the burst. The weather is not good with a bright moon. After stacked 31*300s images, the 3 sigma upper limit is estimated to be R-21 mag from the SDSS magnitude, at the meam time of 4.2 hours after the burst. This message may be cited. for more information about Xinglong GRBs Follow-up observations, please visit the web-site http://www.xinglong-naoc.org/grb/