//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11181 SUBJECT: GRB 100902A: Swift detection of a burst DATE: 10/09/02 19:51:36 GMT FROM: David Palmer at LANL T. Sakamoto (NASA/UMBC), W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester), J. R. Cummings (NASA/UMBC), P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC), J. M. Gelbord (PSU), C. Guidorzi (U Ferrara), S. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU), W.B Landsman (GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL), A. Rowlinson (U Leicester), B. Sbarufatti (INAF-OAB/IASFPA), M. H. Siegel (PSU), M. Stamatikos (OSU/NASA/GSFC), R. L. C. Starling (U Leicester) and M. C. Stroh (PSU) report on behalf of the Swift Team: At 19:31:54 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 100902A (trigger=433160). BAT slewed to the location after a brief delay due to observing constraints. The BAT on-board calculated location is RA, Dec 48.646, +30.973 which is RA(J2000) = 03h 14m 35s Dec(J2000) = +30d 58' 21" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a small spike around the trigger time. There are brighter spikes around T+150 sec and T+200 sec with a duration of 50 sec. The peak count rate was ~1200 counts/sec (15-350 keV), at ~210 sec after the trigger. The XRT began observing the field at 19:37:10.1 UT, 316.2 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source with an enhanced position: RA, Dec 48.6294, 30.9791 which is equivalent to: RA(J2000) = 03h 14m 31.05s Dec(J2000) = +30d 58' 44.8" with an uncertainty of 2.3 arcseconds (radius, 90% containment). This location is 56 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (1.13e+21 cm^-2, Kalberla et al. 2005), with an excess column of 4.1 (+2.41/-2.03) x 10^21 cm^-2 (90% confidence). The initial flux in the 0.1 s image was 2.20e-07 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of nominal 150 seconds with the White filter starting 325 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. Data from the 2.7'x2.7' sub-image are not available at this time. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT 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 0.31. Burst Advocate for this burst is T. Sakamoto (Taka.Sakamoto AT 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: 11182 SUBJECT: GRB 100902A: MASTER Optical Early Limit DATE: 10/09/02 20:22:25 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V.Krushinski, I.Zalozhnich, T.Kopytova, A. Popov Ural State University, Kourovka E. Gorbovskoy, V. Lipunov, V.Kornilov, A.Belinski, N.Shatskiy, N.Tyurina, D.Kuvshinov, P.Balanutsa, V.V.Chazov, P.V.Kortunov, A.Kuznetsov, D.Zimnukhov, M. Kornilov Sternberg Astronomical Institute, Moscow State University K.Ivanov, O.Chuvalaev, V.Poleschuk, E.Konstantinov, V.Lenok, O.Gres, S.Yazev, N.M.Budnev, Irkutsk State University A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory V.Yurkov, Yu.Sergienko, D.Varda, I.Kudelina Blagoveschensk Educational State University, Blagoveschensk MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located at Ural (Kourovka) was pointed to the Swift GRB 100902A (Sakamoto et al., GCN Circ 11181) 27 sec after Notice time (104 s after trigger time) in two polarizations. Thre is no optical transient at XRT position (Sakamoto et al., GCN Circ 1118) brighter 17 mag (exposition 20 s). The message may be cited. mailto: lipunov@sai.msu.ru //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11183 SUBJECT: GRB 100902A: Faulkes Telescope South observations DATE: 10/09/02 20:28:11 GMT FROM: Cristiano Guidorzi at Ferrara U,Italy C. Guidorzi (U. Ferrara), A. Melandri (INAF-OAB), N. Tanvir (U. Leicester) on behalf of a large collaboration report: The 2-m Faulkes Telescope South automatically began observing GRB 100902A (Sakamoto et al. GCN Circ. 11181) on September 02, 19:34:38 UT, 164 seconds from the GRB trigger time and during the major gamma-ray spikes (GCN 11181). Within the XRT error circle we do not find any source down to the following limiting magnitudes: Mid time from Exposure Filter Limiting Magnitude trigger (s) (s) ------------------------------------------------------------ 169 10 R > 15.6 203 3x10 R > 16.0 ------------------------------------------------------------ Calibration is against some nearby USNOB-1 stars. The relatively poor limits are due to the vicinity to the Moon. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11185 SUBJECT: GRB 100902A: MASTER Prompt Optical Observations DATE: 10/09/02 21:02:48 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs E. Gorbovskoy, V. Lipunov, V.Kornilov, A.Belinski, N.Shatskiy, N.Tyurina, D.Kuvshinov, P.Balanutsa, V.V.Chazov, P.V.Kortunov, A.Kuznetsov, D.Zimnukhov, M. Kornilov Sternberg Astronomical Institute, Moscow State University V.Krushinski, I.Zalozhnich, T.Kopytova, A. Popov Ural State University, Kourovka K.Ivanov, O.Chuvalaev, V.Poleschuk, E.Konstantinov, V.Lenok, O.Gres, S.Yazev, N.M.Budnev, Irkutsk State University A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory V.Yurkov, Yu.Sergienko, D.Varda, I.Kudelina Blagoveschensk Educational State University, Blagoveschensk MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located at Ural (Kourovka) was pointed to the Swift GRB 100902A (Sakamoto et al., GCN Circ 11181) 27 sec after Notice time (104 s after trigger time) in two polarizations. Thre is no optical transient at XRT position (Sakamoto et al., GCN Circ 1118) with next limits: start UT end UT t_exp(s) mlim t_start-tGRB(s) Coadd? Filter -------------------------------------------------------------------------- 19:33:38 19:33:58 20 17.0 104.0 N Polariz 19:34:12 19:34:42 30 17.3 132.0 N Polariz 19:34:57 19:35:57 40 17.3 177.0 N Polariz 19:35:51 19:36:41 50 17.4 231.0 N Polariz 19:33:38 19:36:41 140 18.0 104.0 Y Polariz -------------------------------------------------------------------------- The message may be cited. mailto: lipunov@sai.msu.ru //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11188 SUBJECT: GRB 100902A: Enhanced Swift-XRT position DATE: 10/09/03 01:53:07 GMT FROM: Phil Evans at U of Leicester A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) report on behalf of the Swift-XRT team. Using 4941 s of XRT Photon Counting mode data and 6 UVOT images for GRB 100902A, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 48.62930, +30.97904 which is equivalent to: RA (J2000): 03h 14m 31.03s Dec (J2000): +30d 58' 44.5" with an uncertainty of 1.5 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular was automatically generated, and is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11192 SUBJECT: GRB 100902A: optical observation at Mt.Terskol DATE: 10/09/03 11:20:36 GMT FROM: Alexei Pozanenko at IKI, Moscow M. Andreev, A. Sergeev (Terskol Branch of Institute of Astronomy) and A.Pozanenko (IKI) on behalf of larger GRB follow up collaboration report: We observed the field of the Swift GRB 100902A (Sakamoto et al, GCN 11181) with the Z-600 telescope of Mt.Terskol observatory in R-filter between (UT) 00:52:20 - 01:26:40. In enhanced XRT error circle (Beardmore et al, GCN 11188) we do not detect any object. The object at distance of 4" from the center of the enhanced XRT error circle (Beardmore et al, GCN 11188) in coordinates (J2000) RA =03 14 31.35 Dec= +30 58 44.8 with uncertainty of 1" is detected at magnitude R ~ 20 and upper limit of stacked image of R=21 (3 sigma). At present time we cannot confirm variability of the object. The finding chart can be found at http://grb.rssi.ru/GRB100902A/GRB100902A_R_Z600.jpg //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11193 SUBJECT: GRB 100902A: Swift/UVOT Upper Limits DATE: 10/09/03 11:58:54 GMT FROM: Wayne Landsman at GSFC/SSAI W. Landsman (GSFC/Adnet) and T. Sakamoto (NASA/UMBC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 100902A 326 s after the BAT trigger (Sakamoto et al., GCN Circ. 11181). No optical afterglow consistent with the XRT position (Beardmore et al., GCN Circ. 11188) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627) for the first finding chart (FC) exposure and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 326 475 147>20.4 white 326 1008 295>20.8 w1 532 18249 823>20.7 m2 1063 14541 1136>20.8 w2 632 12947 1528>21.2 The values quoted above are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.31 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11194 SUBJECT: GRB 100902A: Swift XRT refined analysis DATE: 10/09/03 13:12:51 GMT FROM: Rhaana Starling at U of Leicester R.L.C. Starling (U. Leicester) and T. Sakamoto (NASA/UMBC) report on behalf of the Swift-XRT team: We have analysed 7.9 ks of XRT data for GRB 100902A (Sakamoto et al. GCN Circ. 11181), from 306 s to 18.2 ks after the BAT trigger. The data comprise 306 s in Windowed Timing (WT) mode (the first 8 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Beardmore et al. (GCN. Circ 11188). The light curve can be modelled with an initial power-law decay with an index of alpha=2.4 (+/-0.1), followed by a break at T+1730 (+/-210) s to an alpha of 0.8 (+/-0.1). Overlaid on this broken power law decay are two large flares, which peak at 400 and 420 s with count rates of 1390 (+/-140) and 1440 (+/-150) count s^-1 respectively. A spectrum formed from all the PC mode data to date can be fitted with an absorbed power-law with a photon spectral index of 2.5 (+/-0.2). The best-fitting absorption column is 3.39 (+/-0.6) x 10^21 cm^-2, in excess of the Galactic value of 1.1 x 10^21 cm^-2 (Kalberla et al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.8 x 10^-11 (9.7 x 10^-11) erg cm^-2 count^-1. We do not report a WT time averaged spectral fit here as this would be affected by the spectral evolution during the flaring activity, evident in the hardness ratio. If the light curve continues to decay with a power-law decay index of 0.8, the count rate at T+24 hours will be 0.013 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 5.7 x 10^-13 (1.4 x 10^-12) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00433160. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11195 SUBJECT: Tentative redshift of GRB100902A from Swift-XRT data DATE: 10/09/03 13:40:08 GMT FROM: Sergio Campana at INAF-OAB S. Campana (INAF-OAB), R. L. C. Starling (U Leicester), P. A. Evans (U Leicester), and T. Sakamoto (NASA/UMBC) report on behalf of the Swift Team: Swift BAT triggered on the early activity of GRB 100902A (Sakamoto et al. 2010, GCN 11181). Swift XRT started observing 316 s after the trigger observing the main event. By using the Swift/XRT spectrum repository at http://www.swift.ac.uk/xrt_spectra/ (see Evans et al. 2009, MNRAS, 397, 1177) we selected two time intervals with an almost constant hardness ratio. These are at the end of the main event between 500-550 s (in Window Timing, WT, mode) and the entire first orbit in Photon Counting (PC) mode (between 600-3000 s). We then fit the two spectra with XSPEC using the model tbabs*ztbabs (cutoff), keeping the same absorption pattern and leaving free the cutoff power-law model for the two spectra (the cutoff power-law model provides much better results in terms of column density evaluation with respect to a simple power-law model when small spectral variations are present). We assume a Galactic column density of 1.1x1021 cm-2 (Kalberla et al. 2005, A&A 440 775) and we allow for a 30% uncertainty in the fit. We fit the spectrum using C-statistics. In the intrinsic column density vs. redshift plane there is just one deep minimum hinting for a redshift z=4.5^+0.3_-0.2 (90% confidence level) and an intrinsic column density N_H(z)=(2.3^+0.5_-0.3)x1023 cm-2. The X-ray spectrum is very soft with Gamma~3.9 at the end of the prompt phase (with a cut-off energy >17 keV) and with Gamma~1.9 and E_cut~5 keV in the PC spectrum. The two spectra indicate the same redshift even separately. The high redshift and the large absorbing column density are in line with the non-detection with UVOT and other ground based optical facilities. The contour plot is available at http://www.brera.inaf.it/utenti/campana/100902.gif //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11196 SUBJECT: GRB 100902A: 1.5m OSN I-band Upper Limits DATE: 10/09/03 18:31:15 GMT FROM: Rubén Sánchez-Ramírez at IAA-CSIC J.C. Tello, R. Sánchez-Ramírez, A. Sota, J. Gorosabel, A.J. Castro-Tirado (IAA-CSIC, Granada), report on behalf of a larger collaboration: "We have carried out I-band observations of the Swift GRB 100902A (Sakamoto et al. GCNC 11181) on Sep 3.1076 - 3.1492 UT (~7.05 hr after the onset of the burst, mean observing time) with the 1.5m telescope at Observatorio de Sierra Nevada, Spain. We do not detect any optical source within the SWIFT/XRT error circle (Beardmore et al. GCNC 11188). The 3 sigma limiting magnitude of the co-added I-band image (Texp=16x200s) is I ~ 21.8, calibrated against the USNO B1.0 catalogue." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11202 SUBJECT: GRB 100902A: Swift-BAT refined analysis DATE: 10/09/04 01:15:41 GMT FROM: Scott Barthelmy at NASA/GSFC M. Stamatikos (OSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team): Using the data set from T-239 to T+963 sec from telemetry downlinks, we report further analysis of BAT GRB 100902A (trigger #433160) (Sakamoto, et al., GCN Circ. 11181). The BAT ground-calculated position is RA, Dec = 48.626, 30.970 deg, which is RA(J2000) = 03h 14m 30.3s Dec(J2000) = +30d 58' 13.2" with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 72%. The mask-weighted light curve shows several strong peaks. The first starts around T-60 sec and returns to background around T+70 sec. We note that this burst location came into the BAT FoV around T-80 sec, so there could have been prior activity for this burst. Then come two stronger peaks at ~T+130 and ~T+205 sec; then a smaller peak at ~T+400 sec. T90 (15-350 keV) is 428.8 +- 43.0 sec (estimated error including systematics). The time-averaged spectrum from T-49.5 to T+409.6 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.98 +- 0.13. The fluence in the 15-150 keV band is 3.2 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+207.89 sec in the 15-150 keV band is 1.0 +- 0.1 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/433160/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11206 SUBJECT: GRB100902A: Optical upper limits at IAO DATE: 10/09/04 13:34:25 GMT FROM: Daisuke Kuroda at OAO/NAOJ D. Kuroda (OAO, NAOJ), H. Hanayama, T. Miyaji, J. Watanabe(IAO, NAOJ), K. Yanagisawa (OAO, NAOJ), M. Yoshida (Hiroshima), K. Ohta (Kyoto) and N. Kawai(Tokyo Tech) report on behalf of the MITSuME collaboration: We observed the field of GRB 100902A (Sakamoto et al. GCNC 11181) with the optical three color (g', Rc and Ic) CCD camera attached to the Murikabushi 1m telescope of Ishigakijima Astronomical Observatory. The observation started on 2010-09-03 18:04:55 UT (~0.94 day after the burst). We did not find any new point source within the Enhanced XRT error circle (Beardmore et al. GCNC 11188) in all the three bands. Three sigma upper limits of the OT are listed below. We used GSC2.3 catalog for flux calibration. T0+[day] MID-UT T-EXP[sec] g' Rc Ic ------------------------------------------------------ 0.94445 18:11:55 720.0 >21.8 >21.4 >20.2 ------------------------------------------------------ T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11209 SUBJECT: GRB 100902A: GROND observations; afterglow candidate DATE: 10/09/04 15:31:29 GMT FROM: Sylvio Klose at TLS Tautenburg A. Updike (Clemson Univ.), A. Nicuesa Guelbenzu, S. Klose (both TLS Tautenburg), and J. Greiner (MPE Garching), report on behalf of the GROND team: GROND (Greiner et al. 2008, PASP 120, 405), the 7-channel imager mounted at the 2.2m ESO/MPI telescope on La Silla, started follow-up observations of GRB 100902A (Sakamoto et al. 2010, GCN 11181) on September 4 at 7:40 UT (about 1.5 days after the trigger). Airmass was around 2. Due to bad weather on La Silla no earlier observations were possible. Within the enhanced 1.5 arcsec XRT error circle (Beardmore et al. 2010, GCN 11188) we find a faint source at coordinates RA, DEC (J2000) = 03:14:30.96, +30:58:44.8 (+/-0.5 arcsec). Preliminary measured AB mags are: r' = 24.1 +/- 0.3 i' = 24.0 +/- 0.4 using GROND zeropoints. At present it is not clear if this is the afterglow or the underling host. No statements about variability or fading can be made at the moment. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11210 SUBJECT: GRB 100902A: UKIRT JK Observation DATE: 10/09/05 07:10:32 GMT FROM: Myungshin Im at Seoul Nat U Myungshin Im, Changsu Choi, Hyunsung Jun, Eugene Kang (CEOU/Seoul National University), Y. Urata (NCU), P. Choi (Pomona College), and T. Sakamoto (NASA/GSFC), on behalf of a larger collaboration We observed GRB 100902A (Sakamoto et al. GCN 11181) in J and K filters using UKIRT. The observation started at Sept. 04, 14:24:39 UT or roughly 1.79 days after the BAT alert. The reduced images with non-optimal calibration frames do not show a clear sign of the afterglow candidate reported in Updike et al. (GCN 11209), although both the J and K images show a faint smudge at the reported location which may corresponds to the afterglow. The significance of the detection is only ~3 sigma (J ~ 20.8 mag, K ~ 19 mag in Vega), therefore it is difficult to draw a firm conclusion on detection or non-detection of the afterglow in our data. Further analysis of the UKIRT data is ongoing. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11339 SUBJECT: GRB 100902A: D50 optical limit DATE: 10/10/13 15:54:24 GMT FROM: Jan Strobl at AI AS CR,Ondrejov Jan Strobl (1,2), Martin Nekola (1), Martin Blazek (1,2), Martin Jelinek (3), Cyril Polasek (1), Petr Kubanek (3,4), Matus Kocka (1) and Rene Hudec (1,2) (1. ASU AVCR Ondrejov, 2. FEL CVUT Praha, 3. IAA Granada, 4. IPL UV Valencia) We report on the observation of the field of the Swift GRB 100902A (Sakamoto et al., GCN 11181) with the 0.5m telescope D50 in Ondrejov (Czech Republic), starting at 22:03:08 UT, i.e. ~2.5h after the trigger. A sequence of 20s unfiltered images was obtained. We coadded 225x20s exposure, obtaining an image with a limitting magnitude Rc~19.1, with an effective exposure time 3.68h after the trigger (23:13 UT). We do not detect any new source within the XRT error circle (Beardmore et al., GCN 11188). This message can be cited. [GCN OPS NOTE(13oct10): Per author's request, the affilation footnotes were fixed.]