//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12794 SUBJECT: GRB 120102A: Swift detection of a burst with an optical counterpart DATE: 12/01/02 02:28:38 GMT FROM: Scott Barthelmy at NASA/GSFC F. E. Marshall (NASA/GSFC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), D. N. Burrows (PSU), N. Gehrels (NASA/GSFC), E. A. Hoversten (PSU), A. Y. Lien (NASA/GSFC/ORAU), C. B. Markwardt (NASA/GSFC), T. Sakamoto (NASA/UMBC), C. J. Saxton (UCL-MSSL), C. A. Swenson (PSU) and T. N. Ukwatta (MSU) report on behalf of the Swift Team: At 02:15:55 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 120102A (trigger=510922). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 276.201, +24.732 which is RA(J2000) = 18h 24m 48s Dec(J2000) = +24d 43' 54" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows an initial small peak and then a much larger peak 32 sec later with a toal duration of about 50 sec. The peak count rate was ~15,000 counts/sec (15-350 keV), at ~33 sec after the trigger. The XRT began observing the field at 02:17:47.9 UT, 112.9 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source located at RA, Dec 276.22495, 24.71375 which is equivalent to: RA(J2000) = 18h 24m 53.99s Dec(J2000) = +24d 42' 49.5" with an uncertainty of 3.7 arcseconds (radius, 90% containment). This location is 102 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 (1.03 x 10^21 cm^-2, Kalberla et al. 2005), with an excess column of 4.1 (+2.17/-1.89) x 10^21 cm^-2 (90% confidence). The initial flux in the 2.5 s image was 4.02e-10 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 121 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at RA(J2000) = 18:24:53.90 = 276.22457 DEC(J2000) = +24:42:47.3 = 24.71314 with a 90%-confidence error radius of about 0.62 arc sec. This position is 3.3 arc sec. from the center of the XRT error circle. The estimated magnitude is 18.04 with a 1-sigma error of about 0.14. No correction has been made for the expected extinction corresponding to E(B-V) of 0.13. 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.) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12795 SUBJECT: GRB 120102A: Enhanced Swift-XRT position DATE: 12/01/02 05:09:12 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 967 s of XRT Photon Counting mode data and 2 UVOT images for GRB 120102A, 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 = 276.22471, +24.71352 which is equivalent to: RA (J2000): 18h 24m 53.93s Dec (J2000): +24d 42' 48.7" 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: 12796 SUBJECT: GRB 120102A: Swift/UVOT Detection DATE: 12/01/02 12:41:27 GMT FROM: Alice Breeveld at MSSL-UCL A. A. Breeveld (MSSL-UCL) and F. E. Marshall (NASA/GSFC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 120102A 121 s after the BAT trigger (Marshall et al., GCN Circ. 12794). A fading source consistent with the XRT position (Beardmore et al., GCN Circ. 12795) is detected in the initial UVOT exposures. The preliminary UVOT position is: RA (J2000) = 18:24:53.89 = 276.22456 (deg.) Dec (J2000) = +24:42:47.1 = 24.71309 (deg.) with an estimated uncertainty of 0.51 arc sec. (radius, 90% confidence). Preliminary detections and 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the finding chart (FC) and early exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white (FC) 121 271 147 18.10 ± 0.06 white 788 1014 167 19.9 ± 0.2 v 663 1239 78 18.16 ± 0.31 b 589 11310 1147 >20.8 u 334 583 246 18.52 ± 0.14 w1 713 6983 452 >20.2 m2 688 6778 452 >20.1 w2 639 12879 1112 >20.9 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.13 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12797 SUBJECT: GRB 120102A: Swift-XRT refined Analysis DATE: 12/01/02 14:28:04 GMT FROM: Phil Evans at U of Leicester O.M. Littlejohns (U. Leicester), G. Stratta (ASDC), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), D.N. Burrows (PSU), J.A. Kennea (PSU), M.C. Stroh (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester) and F.E. Marshall report on behalf of the Swift-XRT team: We have analysed 12 ks of XRT data for GRB 120102A (Marshall et al. GCN Circ. 12794), from 119 s to 34.6 ks after the BAT trigger. The data comprise 240 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Beardmore et al. (GCN. Circ 12795). The late-time light curve (from T0+4.5 ks) can be modelled with an initial power-law decay with an index of alpha=1.99 (+0.27, -0.11), followed by a break at T+13.0 ks to an alpha of 0.97 (+0.27, -0.22). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.04 (+/-0.08). The best-fitting absorption column is 2.59 (+0.26, -0.25) x 10^21 cm^-2, in excess of the Galactic value of 1.0 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 4.0 x 10^-11 (6.2 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 2.59 (+0.26, -0.25) x 10^21 cm^-2 Galactic foreground: 1.0 x 10^21 cm^-2 Excess significance: 10.3 sigma Photon index: 2.04 (+/-0.08) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00510922. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12799 SUBJECT: GRB 120102A: Swift-BAT refined analysis DATE: 12/01/02 15:24:19 GMT FROM: Scott Barthelmy at NASA/GSFC C. B. Markwardt (GSFC), 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), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), 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 recent telemetry downlinks, we report further analysis of BAT GRB 120102A (trigger #510922) (Marshall, et al., GCN Circ. 12794). The BAT ground-calculated position is RA, Dec = 276.224, 24.713 deg, which is RA(J2000) = 18h 24m 53.8s Dec(J2000) = +24d 42' 46.7" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 78%. The mask-weighted light curve shows a weak peak starting at ~T_0 and returning to baseline at ~T+20 sec. The main emission starts at ~T+25 sec with 2, or possibly 3, overlapping peaks, with the peak emission at ~T+33 sec, which then approximately exponentially decays out to 510 sec or possibly out to ~750 sec. At the 3- or 4-sigma level, there is a possible precursor peak at ~T-70 sec with a duration of 10-20 sec. T90 (15-350 keV) is 38.7 +- 3.5 sec (estimated error including systematics). The time-averaged spectrum from T+0.77 to T+53.94 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.59 +- 0.05. The fluence in the 15-150 keV band is 4.3 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+32.75 sec in the 15-150 keV band is 10.3 +- 0.4 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/510922/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12800 SUBJECT: Konus-Wind observation of GRB 120102A DATE: 12/01/03 13:53:11 GMT FROM: Valentin Pal'shin at Ioffe Inst 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 120102A (Swift-BAT trigger=510922: Marshall et al., GCN 12794; Markwardt et al., GCN 12799) triggered Konus-Wind at T0=8181.530 s UT (02:16:21.530). The burst light curve shows a single pulse with a duration of ~15 s. There is a weak precursor marginally seen at ~T0-30 s. As observed by Konus-Wind the burst had a fluence of 1.75(-0.26,+0.30)x10^-5 erg/cm2, and a 256-ms peak flux measured from T0+3.536 s of 5.56(-1.02, +1.12)x10^-6 erg/cm2/s (both in the 20 keV - 4 MeV energy range). The time-integrated spectrum of the burst (from T0 to T0+16.640 s) is well fitted (in the 20 keV - 4 MeV range) by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep), with alpha = -1.47(-0.07, +0.09), and Ep = 805(-180, +288) keV (chi2 = 68.4/73 dof). Fitting by a GRB (Band) model yields the same alpha and Ep, and only an upper limit on the high energy photon index: beta < -2.04. All the quoted results are preliminary. All the quoted errors are at the 90% confidence level. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB120102_T08181/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12801 SUBJECT: GRB 120102A: Fermi GBM observation DATE: 12/01/03 16:58:55 GMT FROM: Shaolin Xiong at UAH S. Xiong (UAH) reports on behalf of the Fermi GBM Team: "At 02:16:23.24 UT on 02 Jan 2012, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 120102A (trigger 347163385 / 120102095), which was also detected by the Swift BAT/XRT/UVOT (F. E. Marshall et al. 2012, GCN 12794) The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight is 84 degrees. The GBM light curve consists of two main pulses with a duration (T90) of about 17 s (50-300 keV). The time-averaged spectrum from T0-1 s to T0+13 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.19 +/- 0.03 and the cutoff energy, parameterized as Epeak, is 380 +/- 33 keV. A Band function fits the spectrum equally well with Epeak = 291 +/- 33 keV, alpha = -1.13 +/- 0.04, and beta = -2.14 +/- 0.13. The event fluence (10-1000 keV) in this time interval is (1.26 +/- 0.03)E-5 erg/cm^2. The 64 ms peak photon flux measured starting from T0+4.8 s in the 10-1000 keV band is 22.8 +/- 1.6 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12875 SUBJECT: GRB 120102A, the review of the sky area in plate archive DATE: 12/01/19 15:43:02 GMT FROM: Valentyna Golovnya at Main Astro Obs,Kyiv V. V. Golovnya (Main Astro Obs, Kyiv) report: We have undertaken the review of the sky area in vicinity of GRB 120102A (A.P. Beardmore et al., GCN Circ.12795) on astronegatives, collected in Ukrainian NAS Main astronomical observatory plate archive (1976-1996). All the plates with the possible object appearance are digitized using Microtek ScanMaker 9800XL TMA and Epson Expression 10000XL flatbed scanners and have been placed into Golosiiv Plate Archive database DBGPA with open access to them. The list of plates is given in the table: YYYYMMDD/TimeUT --Plates--- Exp. LimM Star USNOA2 19890629/211821 EAO040B001801 13.5 16.50 1125-09467284 19890708/212336 GUA040C001487 16.0 16.45 1125-09467782 19890803/192540 GUA040C001492A 16.0 16.00 1125-09466499 19890803/194958 GUA040C001493 16.0 16.00 1125-09466499 19890905/172315 EAO040B001991 13.5 16.50 1125-09467284 Plates-the plate's identifier in GUA040C archive of DWA (D/F=400/2000, M=103"/mm) of the Ukrainian NAS Main Astro obs in Kyiv (Marsden's number - 83) and EAO040B archive of DWAZ (D/F=400/2000, M=103"/mm) of the Engelhardt South. St. Zelenchuk Russia (Marsden's number - 114) [1]. Exp. - Duration of the maximum exposure (minutes). LimM - Limited V mag, derived in the 8 minutes area around the location given in GCN Circ.12795: RA(J2000): 18h 24m 53.93s, Dec(J2000): +24d 42' 48.7" Star USNOA2 - Comparison star. The preview images of 5 areas together with the 8x8 min.of arc area from SkyMap can be found in http://gua.db.ukr-vo.org/img/grb/120102A/index.html The images with full resolution are available via e-mail on demand. References: 1.L.Pakuliak DATABASE of GOLOSIIV PLATE ARCHIVE (DBGPA V2.0), http://gua.db.ukr-vo.org