//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13952 SUBJECT: GRB 121108A: Swift detection of a burst DATE: 12/11/08 17:59:49 GMT FROM: David Palmer at LANL T. N. Ukwatta (MSU), V. D'Elia (ASDC), H. A. Krimm (CRESST/GSFC/USRA), F. E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB), D. M. Palmer (LANL), B. Sbarufatti (INAF-OAB/PSU), M. H. Siegel (PSU) and E. Sonbas (NASA/GSFC/Adiyaman Univ.) report on behalf of the Swift Team: At 17:47:39 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 121108A (trigger=537921). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 83.186, +54.491 which is RA(J2000) = 05h 32m 45s Dec(J2000) = +54d 29' 27" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex peak structure for about 60 seconds, followed by an additional peak at T+120 s. The peak count rate was ~1500 counts/sec (15-350 keV), at ~28 sec after the trigger. The XRT began observing the field at 17:48:33.2 UT, 54.2 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source located at RA, Dec 83.19368, 54.47191 which is equivalent to: RA(J2000) = 05h 32m 46.48s Dec(J2000) = +54d 28' 18.9" with an uncertainty of 4.3 arcseconds (radius, 90% containment). This location is 70 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 consistent with the Galactic value of 1.87 x 10^21 cm^-2 (Kalberla et al. 2005). The initial flux in the 2.5 s image was 1.96e-09 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 63 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of the XRT 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 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 0.37. Burst Advocate for this burst is T. N. Ukwatta (tilan.ukwatta AT gmail.com). 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: 13953 SUBJECT: GRB 121108A: TAROT Calern observatory optical observations DATE: 12/11/08 18:12:31 GMT FROM: Alain Klotz at CESR-CNRS Klotz A. (IRAP-CNRS-OMP), Gendre B. (ASDC/INAF-OAR), Boer M. (UNS-CNRS-OCA), Atteia J.L. (IRAP-CNRS-OMP) report: We imaged the field of GRB 121108A detected by SWIFT (trigger 537921) with the TAROT robotic telescope (D=25cm) located at the Calern observatory, France. The observations started 33.8s after the GRB trigger (19.2s after the notice). The elevation of the field increased from 20 degrees above horizon and weather conditions were good for the first images and became cloudy. The first image is trailed with a duration of 60.0s (see the description in Klotz et al., 2006, A&A 451, L39). We do not detect any OT with a limiting magnitude of: t0+33.8s to t0+93.8s : R > 15.8 The second image is 90.0s exposure in tracking mode: t0+417.6s to t0+507.6s : R > 16.5 Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction. N.B. Galactic coordinates are lon=156.8411 lat=+11.3702 and the galactic extinction in R band is about 1.0 magnitude estimated from D. Schlegel et al. 1998ApJ...500..525S. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13954 SUBJECT: GRB 121108A: MASTER early prompt optical limit DATE: 12/11/08 19:33:45 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina, N.Shatskiy, P.Balanutsa, D.Zimnukhov, A.Kuznetsov, V.V.Chazov, D.Denisenko, A.Sankovich Sternberg Astronomical Institute, Moscow State University A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov Blagoveschensk Educational State University, Blagoveschensk K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk Irkutsk State University V.Krushinski, I.Zalozhnih, A. Popov Ural Federal University, Kourovka Hugo Levato and Carlos Saffe Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE) Claudio Mallamaci, Carlos Lopez and Federico Podest Observatorio Astronomico Felix Aguilar (OAFA) MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Kislovodsk was pointed to the GRB121108A (Ukwatta et. al. GCN13952) 36 sec after notice time and 54 sec after GRB time at 2012-11-08 17:48:33.174 UT in two polarizations. On our first (10s exposure) set we haven`t found optical transient within SWIFT error-box. The 5-sigma upper limit has been about 15.8 mag The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13955 SUBJECT: GRB 121108A: Weihai observatory optical observations DATE: 12/11/08 20:02:23 GMT FROM: Dong Xu at DARK/NBI D. Xu (DARK/NBI), J.-M. Ai, C. Cao, S.-M. Hu (SDU) report: We observed the field of GRB 121108A (Ukwatta et al., GCN 13952) using the 1m telescope located at Weihai, Shandong Province, China. Observations started at 18:10 UT on 2012-11-08 (i.e., 22 mins after the BAT trigger) and 4x600s exposures in the R filter were obtained. No optical source was found within the enhanced XRT error circle down to a limit of R~20.5 mag (3sigma), calibrated with the USNO B1 catalog. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13956 SUBJECT: GRB 121108A: MITSuME Ishigakijima upper limits DATE: 12/11/09 01:38:02 GMT FROM: Daisuke Kuroda at OAO/NAOJ D. Kuroda (OAO, NAOJ), H. Hanayama, T. Miyaji, J. Watanabe (IAO, NAOJ), K. Yanagisawa (OAO, NAOJ), S.Nagayama (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 121108A (Ukwatta et al., GCNC 13952) 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 2012-11-08 18:29:39 UT (~42 min after the burst). We did not find any new point source within the XRT circle (Ukwatta et al., GCNC 13952) 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 ------------------------------------------------------ 0.06526 19:21:37 5820.0 >22.6 >22.0 >20.0 ------------------------------------------------------ T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13957 SUBJECT: GRB 121108A: Optical observations DATE: 12/11/09 04:37:07 GMT FROM: Shashi Bhushan Pandey at ROTSE Brajesh Kumar, Sumit Jaiswal and S.B. Pandey (ARIES, Nainital, India, on behalf of larger Indian GRB collaboration). Swift GRB 121108A (Ukwatta et al., GCN 13952) was observed with the 1.3m Devasthal Fast Optical Telescope at Nainital. Three images in R_c pass-band (300s each) were obtained starting at 2012-11-08 19:56:19 (UT). In the co-added R_c frame (300s x 3), we did not detect any optical source within the XRT error-box down to a limiting magnitude of ~21 mag. This massage may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13958 SUBJECT: GRB 121108A : Lulin/TRIPOL2 Optical Limits DATE: 12/11/09 06:41:31 GMT FROM: Yuji Urata at Nat. Central U. C.D. Lee, Y. Urata (NCU), K.Y. Huang (ASIAA) on behalf of EAFON: "We imaged the field of GRB 121108A (Ukwatta et al. GCN 13952) with the Triple Range Imager and POLarimeter 2 (TRIPOL2) attached to the Lulin 1m telescope. The simultaneous three color observations were started on 2012-11-08 20:12:18.2 UT (~2.41 hrs after the burst). There is no new sources in the error region of the X-ray afterglow reported by Ukwatta et al. (GCN 13952) with three sigma limits of g~20.6, r~20.5 and i~20.2 mag (at 2.92 hrs after the burst)." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13959 SUBJECT: GRB 121108A: Enhanced Swift-XRT position DATE: 12/11/09 07:29:21 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 1705 s of XRT Photon Counting mode data and 2 UVOT images for GRB 121108A, 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 = 83.19408, +54.47352 which is equivalent to: RA (J2000): 05h 32m 46.58s Dec (J2000): +54d 28' 24.7" with an uncertainty of 1.8 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: 13960 SUBJECT: GRB 121108A: Xinglong TNT upper limit DATE: 12/11/09 12:22:18 GMT FROM: L.P. Xin at NAOC L. P. Xin, Y. L. Qiu, J. Y. Wei, J. Wang, J. S. Deng, C. Wu, X. H. Han on behalf of EAFON report: We began to observe GRB121108A ( Ukwatta et al., GCN 13952 ) with Xinglong TNT telescope at 17:49:47 (UT), about 128s after the burst. A series of white and R-band images were obtained. No any optical counterpart was found in the X-ray errorbox (Beardmore et al., GCN 13959). The 3 sigma upper limit is about 19.9 mag in R-band calibrated by USNO B1.0 R2 mag, at the mean time of 58 min after the burst. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13961 SUBJECT: GRB 121108A, Swift-BAT refined analysis DATE: 12/11/09 14:24:40 GMT FROM: Tilan Ukwatta at MSU W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), G. Sato (ISAS), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team): Using the data set from T-240 to T+962 sec from the recent telemetry downlink, we report further analysis of BAT GRB 121108A (trigger #537921) (Ukwatta, et al., GCN Circ. 13952). The BAT ground-calculated position is RA, Dec = 83.216, 54.520 deg which is RA(J2000) = 05h 32m 51.9s Dec(J2000) = +54d 31' 11.2" with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 90%. BAT light curve shows two multi-peak episodes. First one starts at the trigger time and lasts for about 50 seconds and the second weak episode starts around T+130 seconds and lasts for about 40 seconds. T90 (15-350 keV) is 89 +- 48 sec (estimated error including systematics). The time-averaged spectrum from T-0.15 to T+137.98 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.28 +- 0.20. The fluence in the 15-150 keV band is 9.6 +- 1.2 x 10^-07 erg/cm2. The 1-sec peak photon flux measured from T+43.18 sec in the 15-150 keV band is 1.6 +- 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/537921/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13962 SUBJECT: GRB 121108A: Swift/UVOT Upper Limits DATE: 12/11/09 18:03:29 GMT FROM: Frank Marshall at GSFC F. E. Marshall (NASA/GSFC) and T. N. Ukwatta (MSU) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 121108A 64 s after the BAT trigger (Ukwatta et al., GCN Circ. 13952). No optical afterglow consistent with the XRT position (Beardmore et al. GCN Circ. 13959) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 64 213 147 >20.9 u_FC 276 526 246 >20.5 white 64 1721 412 >21.3 v 605 1771 136 >19.6 b 531 1697 117 >19.9 u 276 1672 362 >20.6 w1 655 1814 129 >19.6 m2 1429 1623 39 >19.6 w2 581 1747 136 >19.8 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.37 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13963 SUBJECT: GRB 121108A: Swift-XRT refined Analysis DATE: 12/11/10 17:14:07 GMT FROM: Andrea Melandri at INAF-OAB A. Melandri (INAF-OAB) and T. N. Ukwatta (MSU) report on behalf of the Swift-XRT team: We have analysed 24 ks of XRT data for GRB 121108A (Ukwatta et al. GCN Circ. 13952), from 47 s to 82.6 ks after the BAT trigger. The data comprise 129 s in Windowed Timing (WT) mode (the first 6 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 13959). The light curve (from T0+0.8 ks) can be modelled with a power-law decay with a decay index of alpha=1.0 (+/-0.1). Flare activity is detected from T0+100 and T0+200 s after the burst event. A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.60 (+/-0.09). The best-fitting absorption column is 3.6 (+0.5, -0.4) x 10^21 cm^-2, in excess of the Galactic value of 1.9 x 10^21 cm^-2 (Kalberla et al. 2005). The PC mode spectrum has a photon index of 1.70 (+0.20, -0.18) and a best-fitting absorption column of 2.3 (+0.7, -0.4) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.6 x 10^-11 (6.0 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 2.3 (+0.7, -0.4) x 10^21 cm^-2 Galactic foreground: 1.9 x 10^21 cm^-2 Excess significance: <1.6 sigma Photon index: 1.70 (+0.20, -0.18) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00537921. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13981 SUBJECT: GRB 121108A: optical upper limit DATE: 12/11/21 17:12:37 GMT FROM: Alexei Pozanenko at IKI, Moscow V. Rumyantsev, N.Pit' (CrAO), А. Volnova (SAI MSU, IKI), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of the Swift GRB 121108A (Ukwatta et al., GCN 13952) with AZT-11 telescope of CrAO observatory starting on Nov. 08 (UT) 18:07:04. We took several images in R-filter of 180 s exposure. Within enhanced XRT afterglow position (Beardmore et al., GCN 13959) we do not detect any new object. A photometry of co-added frame is based on the USNO-B1.0 (R2) nearby stars is following: T0+, Filter Exposure, OT, UL (3 sigma) mid, d (s) 0.02395 R 10x180 n/d 18.9