//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14607 SUBJECT: GRB 130508A: Swift detection of a probable burst DATE: 13/05/08 17:44:12 GMT FROM: Scott Barthelmy at NASA/GSFC S. T. Holland (STScI), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), D. N. Burrows (PSU), J. R. Cummings (NASA/UMBC), V. D'Elia (ASDC), J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA), D. Malesani (DARK/NBI), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester), B. Sbarufatti (INAF-OAB/PSU), M. H. Siegel (PSU), E. Troja (NASA/GSFC/UMCP) and B.-B. Zhang (PSU) report on behalf of the Swift Team: At 17:08:53 UT, the Swift Burst Alert Telescope (BAT) triggered and located a probable GRB 130508A (trigger=555413). Swift slewed immediately to the source location. The BAT on-board calculated location is RA, Dec 305.312, +34.949 which is RA(J2000) = 20h 21m 15s Dec(J2000) = +34d 56' 58" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The real-time lightcurve shows a weak peak with a duration of about 40 sec. The peak count rate was ~1000 counts/sec (15-350 keV), at ~18 sec after the trigger. The XRT began observing the field at 17:11:03.9 UT, 130.5 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source with an enhanced position: RA, Dec 305.3217, 34.9583 which is equivalent to: RA(J2000) = 20h 21m 17.20s Dec(J2000) = +34d 57' 29.9" with an uncertainty of 2.5 arcseconds (radius, 90% containment). This location is 44 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. We cannot determine whether the source is fading at the present time. The on-board calculated light curve shows evidence for a strong flare in Windowed Timing mode data at about 145-150 s after the BAT trigger. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (7.72 x 10^21 cm^-2, Kalberla et al. 2005), with an excess column of 1 (+1.60/-1.01) x 10^22 cm^-2 (90% confidence). UVOT took a finding chart exposure of 150 seconds with the White filter starting 135 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 large, but uncertain extinction expected. Even though this is a weak detection and it is on the Galactic Plane (lon,lat= 74,-1), we determine that this is probably a GRB, but can not rule out some other type of astrophysical source. We will need the full data set to make the determination. Burst Advocate for this burst is S. T. Holland (sholland AT stsci.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: 14609 SUBJECT: GRB130508A: BOOTES-3 optical limit DATE: 13/05/08 19:34:53 GMT FROM: Juan Carlos Tello at IAA-CSIC J.C. Tello, R. Sánchez-Ramirez, M. Jelinek (IAA-CSIC Granada), J. Gorosabel (UPV/EHU-IAA/CSIC), W. Allen (Vintage Lane Obs.), Ph. Yock (Auckland Univ.), P. Kubanek (IP AS CR & IAA-CSIC), and A. J. Castro-Tirado (IAA-CSIC) report on behalf of a larger collaboration: "We observed the field of GRB 130508A (Holland et al., GCNC 14607), detected by Swift/BAT, with the 0.6m Yock-Allen robotic telescope (BOOTES-3) located in Blenheim, New Zealand. Unfiltered images were obtained starting 17:10:28UT (94 seconds after the burst, 17.65s after receiving the first GCN packet). The combined exposure of 120 images of 0.5 seconds each revealed no uncatalogued sources within the XRT uncertainty circle down to a magnitude of R Mag~15 when compared to the USNO-B1 catalogue. Further images of longer exposure revealed no other sources and did not provide a significantly better limit." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14611 SUBJECT: GRB 130508A: MITSuME Okayama upper limits DATE: 13/05/09 00:17:17 GMT FROM: Daisuke Kuroda at OAO/NAOJ D. Kuroda, K. Yanagisawa, Y. Shimizu, H. Toda (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 130508A (Holland et al., GCNC 14607) with the optical three color (g', Rc and Ic) CCD camera attached to the MITSuME 50cm telescope of Okayama Astrophysical Observatory. The observation started on 2013-05-08 17:10:40 UT (~1.8 min after the burst). We did not find any new point source within the XRT error circle (Holland et al., GCNC 14607) in all the three bands. Photometric results of the OT are listed below. We used GSC2.3 catalog for flux calibration. #T0+[day] MID-UT T-EXP[sec] g' Rc Ic ----------------------------------------------------- 0.04312 18:10:59 6360.0 >20.5 >20.4 >19.1 ----------------------------------------------------- T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14613 SUBJECT: GRB 130508A, Swift-BAT refined analysis DATE: 13/05/09 10:46:07 GMT FROM: Jay R. Cummings at NASA/GSFC/Swift T. Sakamoto (AGU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), S. T. Holland (STScI), H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/GSFC/ORAU), C. B. Markwardt (GSFC), D. M. Palmer (LANL), 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-60 to T+243 sec from the recent telemetry downlink, we report further analysis of BAT GRB 130508A (trigger #555413) (Holland, et al., GCN Circ. 14607). The BAT ground-calculated position is RA, Dec = 305.351, 34.966 deg which is RA(J2000) = 20h 21m 24.2s Dec(J2000) = +34d 57' 57.6" with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 60%. The mask-weighted light curve shows a single peak from about T+9 to T+55 sec. T90 (15-350 keV) is 42 +- 11 sec (estimated error including systematics). The time-averaged spectrum from T+9.62 to T+56.75 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.80 +- 0.23. The fluence in the 15-150 keV band is 6.6 +- 1.0 x 10^-07 erg/cm2. The 1-sec peak photon flux measured from T+11.07 sec in the 15-150 keV band is 0.7 +- 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/555413/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14614 SUBJECT: GRB 130508A: Refined Swift-XRT analysis: Correction to GCN 14612 DATE: 13/05/09 11:03:24 GMT FROM: Phil Evans at U of Leicester P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: GCN 14126 was sent in error, with several pieces of information missing, as new data were being processed as the circular was sent. The corrected refined XRT analysis is as follows: We have analysed 10 ks of XRT data for GRB 130508A (Holland et al. GCN Circ. 14607), from 134 s to 45.8 ks after the BAT trigger. The data comprise 53 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The best available XRT position (using the promptly downlinked event data, the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue) is RA, Dec = 305.3218, 34.9583 which is equivalent to: RA (J2000): 20 21 17.22 Dec(J2000): +34 57 29.9 with an uncertainty of 2.5 arcsec (radius, 90% confidence). The light curve can be modelled with a power-law decay with a decay index of alpha=1.98 (+0.39, -0.28). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.0 (+0.6, -0.5). The best-fitting absorption column is 1.6 (+1.0, -0.8) x 10^22 cm^-2, in excess of the Galactic value of 7.7 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 1.0 x 10^-10 (1.3 x 10^-10) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 1.6 (+1.0, -0.8) x 10^22 cm^-2 Galactic foreground: 7.7 x 10^21 cm^-2 Excess significance: 1.7 sigma Photon index: 1.0 (+0.6, -0.5) If the light curve continues to decay with a power-law decay index of 1.98, the count rate at T+24 hours will be 6.0 x 10^-6 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 6.1 x 10^-16 (7.8 x 10^-16) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00555413. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14616 SUBJECT: GRB 130508A: RATIR Optical and NIR Observations DATE: 13/05/09 16:42:06 GMT FROM: Nat Butler at Az State U Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB) J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UCSC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), José A. de Diego (UNAM), Leonid Georgiev (UNAM), Jesús González (UNAM), Carlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report: We observed the field of GRB 130508A (Holland, et al., GCN 14607) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir from 2013/05 9.36 to 2013/05 9.45 UTC (15.45 to 17.54 hours after the BAT trigger), obtaining a total of 1.42 hours exposure in the r' and i' bands and 0.60 hours exposure in the Z, Y, J, and H bands. For a source within the Swift-XRT error circle (Evans et al., GCN 14614), in comparison with USNO-B1 and 2MASS, we obtain the following upper limits (3-sigma): r' > 23.81 i' > 23.53 Z > 21.95 Y > 21.66 J > 21.00 H > 20.42 These magnitudes are in the AB system and not corrected for Galactic extinction in the direction of the GRB. We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14618 SUBJECT: GRB 130508A: MITSuME Akeno upper limits DATE: 13/05/10 13:04:03 GMT FROM: Yoichi Yatsu at Tokyo Tech. Y. Saito, Y. Yano, R. Usui, Y. Tachibana, K. Ito, T. Yoshii, S. Kurita, Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration: We observed the field of GRB 130508A (Holland et al., GCNC 14607) with the optical three color (g, Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope of Akeno Observatory, Yamanashi, Japan. The observation started on 2013-05-08 17:10:32 UT ( ~99 sec after the burst). And we could not find any new point source within the XRT error circle (Holland et al., GCNC 14607) in all the three bands. The results of photometry (3 sigma upper limits) are listed below. We used GSC2.3 catalog for flux calibration. T0+[sec] MID-UT T-EXP[sec] g' Rc Ic ------------------------------------------------------------ ------------------------------- 283 17:13:30 240 >19.4 >19.1 >18.0 2803 17:55:30 4320 >20.7 >20.4 >19.1 ------------------------------------------------------------ ------------------------------- T0+ : Elapsed time after the burst [sec] T-EXP: Total Exposure time [sec] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14619 SUBJECT: GRB 130508A: Swift/UVOT Upper Limits DATE: 13/05/10 20:39:01 GMT FROM: Stephen Holland at STScI S. T. Holland (STScI) reports on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 130508A starting 136 s after the BAT trigger (Holland et al. 2013, GCNC 14607). We do not detect any new source consistent with the UVOT-enhanced XRT position (Evans 2013, GCNC 14614) in any of the UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the finding chart (FC) exposures and initial summed exposures are presented below. Filter TSTART TSTOP Exposure Mag ------------------------------------------------- white (FC) 136 285 147 >20.8 u (FC) 296 545 246 >19.8 ------------------------------------------------- v 4416 5642 393 >20.0 b 551 6336 288 >20.5 u 296 6257 639 >20.5 uvw1 4417 6052 393 >20.3 uvm2 4212 5847 393 >20.3 uvw2 3801 5437 393 >20.5 white 136 5231 344 >21.5 ------------------------------------------------- The quoted upper limits have not been corrected for the expected extinction due to the Galactic reddening along the line of sight to this burst of E(B-V) = 2.54 mag (Schlafly et al. 2011, ApJS, 737, 103). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14629 SUBJECT: GRB130508A: MASTER-Net optical observations DATE: 13/05/13 07:13:31 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk Irkutsk State University 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 V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov Blagoveschensk Educational State University, Blagoveschensk A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory 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 Tunka was pointed to the GRB130508A 37 sec after notice time and 119 sec after GRB time at 2013-05-08 17:10:52.959 UT. On our first (20s exposure) set we haven`t found optical transients within SWIFT error-box (Holland et al. GCN14607). The 5-sigma upper limit has been about 17.3 mag The message may be cited.