//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10253 SUBJECT: GRB 091208: Swift detection of a burst DATE: 09/12/08 08:56:56 GMT FROM: David Palmer at LANL E. A. Hoversten (PSU), P. A. Evans (U Leicester), C. Gronwall (PSU), J. Mao (INAF-OAB), C. B. Markwardt (CRESST/GSFC/UMD), P. T. O'Brien (U Leicester), K. L. Page (U Leicester), D. M. Palmer (LANL), M. Stamatikos (OSU/NASA/GSFC) and L. Vetere (PSU) report on behalf of the Swift Team: At 08:46:00 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 091208 (trigger=378554). Swift could not slew to the burst due to an Earth limb constraint. The BAT on-board calculated location is RA, Dec 0.274, +65.674 which is RA(J2000) = 00h 01m 06s Dec(J2000) = +65d 40' 25" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a FRED structure with a duration of about 30 sec. The peak count rate was ~6000 counts/sec (15-350 keV), at ~0 sec after the trigger. Due to an observing constraint, Swift will not slew until T0+49.7 minutes. There will be no XRT or UVOT data until this time. Burst Advocate for this burst is E. A. Hoversten (hoversten 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: 10254 SUBJECT: GRB 091208: ROTSE-III Optical Limits DATE: 09/12/08 09:16:45 GMT FROM: Fang Yuan at ROTSE F. Yuan (U Mich), W. Rujopakarn (Steward), W. Zheng (U Mich), report on behalf of the ROTSE collaboration: ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 091208 (Swift trigger 378554; E. A. Hoversten et al, GCN 10253), producing images beginning 9.6 s after the GCN notice time. An automated response took the first image at 08:46:30.5 UT, 30.0 s after the burst. We took 10 5-sec and 42 20-sec exposures. These unfiltered images are calibrated relative to USNO A2.0 (R). Imaging is on going. Comparison to the DSS (second epoch) reveals no new sources within the 3-sigma Swift/BAT error circle, for both single images and coadding into sets of 10. Individual images have limiting magnitudes ranging from 14.6-16.6; we set the following specific limits. start UT end UT t_exp(s) mlim t_start-tGRB(s) Coadd? -------------------------------------------------------------------- 08:52:40.1 08:57:21.5 281 17.3 399.6 Y 08:57:30.2 09:02:12.0 281 17.4 689.7 Y //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10261 SUBJECT: GRB 091208A, RIMOTS optical upper limits DATE: 09/12/08 13:40:03 GMT FROM: Kazuhiro Noda at Miyazaki U K.Noda, K.Kono, E.Sonoda, N.Ohmori, H.hayasi, A.Daikyuji, Y.Nisioka, M.Yamauchi (University of Miyazaki) We have observed the field covering the error circle of GRB GRB091208A (Swift trigger 378554, GCN 10253, Hoversten et al.) with the unfiltered CCD camera on the 30-cm telescope at University of Miyazaki. The observation was started 09:04:56 UT, about 19 min after the Swift trigger time. We have compared our data of 30 sec exposures with the USNO-A2.0 catalog, There is no new source at the reported position. the upper limits are as follows: -------------------------------------------------------------- Start(UT) End(UT) Num. of frames Limit (mag.) -------------------------------------------------------------- 09:04:56 09:05:26 1 15.8 09:04:56 09:48:39 33 17.3 --------------------------------------------------------------- //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10264 SUBJECT: GRB 091208A Swift-BAT refined analysis DATE: 09/12/08 15:58:56 GMT FROM: Jay R. Cummings at NASA/GSFC/Swift S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), E. A. Hoversten (PSU), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team): Using the data set from T-61 to T+242 sec from the recent telemetry downlink, we report further analysis of BAT GRB 091208A (trigger #378554) (Hoversten, et al., GCN Circ. 10253). The BAT ground- calculated position is RA, Dec = 0.295, 65.680 deg which is RA(J2000) = 00h 01m 10.9s Dec(J2000) = +65d 40' 47.7" with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 88%. The mask-weighted light curve shows a single FRED with some additional structure on the decaying side. The tail appears to be quite long at low energy, with emission detectable for up to 200 seconds after the trigger. T90 (15-350 keV) is 29.1 +- 2.5 sec (estimated error including systematics). The time-averaged spectrum from T-0.3 to T+32.8 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 0.81 +- 0.10. The fluence in the 15-150 keV band is 1.5 +- 0.1 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T+0.15 sec in the 15-150 keV band is 1.8 +- 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/378554/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10270 SUBJECT: GRB 091208A: Swift-XRT observations DATE: 09/12/08 22:24:53 GMT FROM: Claudio Pagani at PSU/Swift-XRT C. Pagani, L. Vetere (PSU), P.A. Evans (U. Leicester), J. L. Racusin (NASA/GSFC) and E. A. Hoversten (PSU) report on behalf of the Swift Team: Swift/XRT observed the field of GRB 091208A (BAT trigger number 378554; Hoversten et al. GCN Circ. 10253) from 3.1 ks to 3.3 ks after the BAT trigger and again from 25 ks to 27 ks after the BAT trigger. The first observation was delayed due to an observing constraint. During the first observation no X-ray afterglow is detected inside the BAT error circle (Barthelmy et al. GCN Circ. 10264) in 180 seconds of Photon Counting data. The corresponding 3-sigma upper limit is 0.04 counts/s. For comparison, the median XRT count rate for long GRB afterglows at 3 ks after the BAT trigger is approximately 0.1 counts/s. During the second observation no X-ray afterglow is detected inside the BAT error circle in 694 seconds of PC data. The corresponding 3-sigma upper limit is 0.01 counts/s. For comparison, the median XRT count rate for long GRB afterglows at 25 ks after the BAT trigger is approximately 0.02 counts/s. Based on the count rates of the XRT afterglows observed during the Swift mission the chance of detecting a long GRB with the XRT in a 1 ks observation 25 ks after the BAT trigger is 61%. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10274 SUBJECT: GRB091208A: Swift/UVOT refined analysis DATE: 09/12/09 13:43:27 GMT FROM: Massimiliano de Pasquale at MSSL-UCL M. De Pasquale (MSSL/UCL) and E. Hoversten (PSU) report on the behalf of the Swift team: Swift/UVOT observed the field of GRB091208A from 4.32 ks to 4.33 ks after the BAT trigger in the v filter and then from 26.01 to 26.71 ks after the trigger in u, v and white filters. No new source is detected in the BAT error circle (Barthelmy et al., GCN Circ. 10264). We caution though that a small fraction of BAT error circle is not covered by UVOT exposures. 3 sigma upper limits on magnitudes are as follows: Filter T_start(s) T_stop(s) Exp(s) Mag v 4318 4328 10 >17.4 v 26513 26717 200 >19.4 wh 26261 26507 243 >21.1 u 26008 26255 243 >20.1 The values quoted above are on the UVOT Photometric System (Poole et al., 2008, MNRAS 383,627). They are not corrected for the expected strong Galactic extinction, corresponding to a reddening of E(B-V)=1.6. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10276 SUBJECT: Konus-Wind observation of GRB 091208A DATE: 09/12/10 16:47:11 GMT FROM: Dmitry Frederiks at Ioffe Institute S. Golenetskii, R.Aptekar, D. Frederiks, E. Mazets, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, report: The long GRB 091208A (Swift-BAT trigger #378554: Hoversten et al., GCN 10253; Barthelmy et al., GCN 10264) triggered Konus-Wind at T0=31563.038s UT (08:46:03.038). The burst light curve shows a smooth single-pulse structure with a total duration of ~30 s. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB091208_T31563/ As observed by Konus-Wind the burst had a fluence of 6.2(+/-1.0)x10-6 erg/cm2, and a 256-ms peak flux measured from T0-0.256s of 1.3(+/-0.2)x10-6 erg/cm2/s (both in the 20 keV - 2 MeV energy range). The time-integrated spectrum of the burst (from T0 to T0+24.832 s) can be fitted in the 20 keV - 2 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep), with alpha = +0.24(-0.5, +0.7), and Ep = 314(-50, +70) keV (chi2 = 74/61 dof). The spectrum of the most intense part of the burst (measured from T0 to T0+8.448 s) is well fitted in the 20 keV - 2 MeV range by a power law with exponential cutoff model, for which alpha = +0.13(-0.4, +0.55), and Ep = 316(-44, +60) keV (chi2 = 47/61 dof). All the quoted results are preliminary. All the quoted errors are at the 90% confidence level. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10277 SUBJECT: GRB 091208A: GAO 150cm telescope Optical Observation DATE: 09/12/11 11:19:27 GMT FROM: Kenzo Kinugasa at Gunma Astro. Obs/Japan K. Kinugasa, S. Honda, H. Takahashi, H. Taguchi, O. Hashimoto (Gunma Astronomical Observatory) report: The field of GRB 091208A (Hoversten et al. GCN 10253) was observed with the 150 cm telescope of Gunma Astronomical Observatory. Starting at 09:09:06 UT on Dec.8 ( 23.1 min after the trigger), both Rc and Ic frames were acquired for sets of 5 x 0.5-min and 3 x 2-min exposures. The limiting magnitude in combined image is estimated as Rc~20.5 and Ic~20.0. We did not detect any new point source within the BAT error circle down to the magnitudes of R~20.2 and I~19.5 relative to USNO-B1.0 R2 and I magnitudes, respectively. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10278 SUBJECT: GRB 091208A: Suzaku WAM observation of the prompt emission DATE: 09/12/12 04:00:04 GMT FROM: Yusuke Nishioka at Miyazaki U. Y. Nishioka, H. Hayashi, N. Ohmori, A. Daikyuji,E. Sonoda, K. Kono, K. Noda, M. Yamauchi (Univ. of Miyazaki), T. Sugasahara, M. Tashiro, Y. Terada, A. Endo, K. Onda, W. Iwakiri (Saitama U.), S. Sugita (Nagoya U.), K. Yamaoka (Aoyama Gakuin U.), M. Ohno, M. Suzuki, M. Kokubun, T. Takahashi (ISAS/JAXA), Y. E. Nakagawa, T. Tamagawa (RIKEN), N. Vasquez (Tokyo Tech.), Y. Urata, H.M Lin (NCU), Y. Hanabata, T. Uehara, T. Takahashi, Y. Fukazawa (Hiroshima U.), T. Enoto, K. Nakazawa, K. Makishima (Univ. of Tokyo), S. Hong (Nihon U.), on behalf of the Suzaku WAM team, report The long GRB 091208A (Swift/BAT trigger #378554 ; Barthelmy et al., GCN 10264) triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 2009-12-08 08:46:00.546 UT (=T0). The observed light curve shows a single peak starting at T0 s, ending at T0+10 s with a duration (T90) of about 6.6 seconds. The fluence in 100 - 1000 keV was 4.85(-0.99, +0.65) x10^-6 erg/cm^2. The 1-s peak flux measured from T0 s was 1.94 (-0.60, +0.61) photons/cm^2/s in the same energy range. Preliminary result shows that the time-averaged spectrum from T0-0.5 s to T0+10 s is well fitted by a single power-law with a photon index of 2.04 (-0.24, +0.28) (chi^2/d.o.f = 48.5/33). All the quoted errors are at statistical 90% confidence level, in which the systematic uncertainties are not included. The light curves for this burst are available at: http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html