//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14266 SUBJECT: GRB 130306A: Swift detection of a burst DATE: 13/03/07 00:07:17 GMT FROM: Scott Barthelmy at NASA/GSFC M. H. Siegel (PSU), B. N. Barlow (PSU), S. D. Barthelmy (GSFC), N. Gehrels (NASA/GSFC), D. Grupe (PSU), D. Malesani (DARK/NBI), C. B. Markwardt (NASA/GSFC), F. E. Marshall (NASA/GSFC), C. J. Mountford (U Leicester), D. M. Palmer (LANL) and B.-B. Zhang (PSU) report on behalf of the Swift Team: At 23:51:01 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 130306A (trigger=550457). Swift did not slew because of a Moon constraint. The BAT on-board calculated location is RA, Dec 279.478, -11.692 which is RA(J2000) = 18h 37m 55s Dec(J2000) = -11d 41' 29" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT real-time TDRSS light curve shows nothing significant as is typical for image triggers. Due to a Moon observing constraint, Swift cannot slew to the BAT position until 05:58 UT on 2013 March 08. There will thus be no XRT or UVOT data for this trigger before this time. We note that this burst was strongly detected by Fermi GBM in a 4.096 second trigger at T-216 seconds (Trigger 384306448) at a location consistent with the BAT location. Swift was slewing at the time of the Fermi Trigger, detecting the afterglow of the GRB in its first 64 second image trigger after the slew ended. Burst Advocate for this burst is M. H. Siegel (siegel AT swift.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: 14269 SUBJECT: GRB 130306A: MASTER-Net pre-Swift alert observation DATE: 13/03/07 15:05:43 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Denisenko, D.Kuvshinov, N.Tyurina, N.Shatskiy, P.Balanutsa, D.Zimnukhov, A.Kuznetsov, V.V.Chazov, 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 GRB130306A 59 sec after Fermi trigger num 384306448 at 2013-03-06 23:48:24.313 UT, i.e. 157 sec before Swift trigger time (Siegel et. al. GCN14266). The observations started on very high zenith distance about 85 deg. SWIFT error box (Siegel et. al. GCN14266) got on the edge of our FOV. On our first (10s exposure) set we haven't found optical transient within SWIFT error box. The 5-sigma upper limit has been about 13 mag. Next time we pointed to BAT position at 2013-03-06 23:52:44.60 UT by SWIFT alert. On our first (20s exposure) set we haven't found optical transient within SWIFT error-box with upper limit 15.2m. On coadd image of 8 sets with total exposure 420 sec upper limit is 17.0m (5-sigma). Galactic extinction in the direction of GRB 130306 is A_R=3.7, A_I=2.7 (from to Schlegel et al., 1998) and A_R=3.0, A_I=2.1 (according to Schlafly et al., 2011). The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14270 SUBJECT: GRB 130306A: Fermi GBM observation DATE: 13/03/08 02:56:56 GMT FROM: Veronique Pelassa at UAH V. Pelassa (UAH) reports on behalf of the Fermi GBM Team: "At 23:47:25.57 UT on March 6 2013, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 130306A (trigger 384306448 / 130306991), which was also detected by the Swift/BAT (Siegel et al. 2013, GCN 14266) The GBM on-ground location is consistent with the Swift position. The GRB is observed at high angles to all GBM NaI detectors and the angle from the LAT boresight is 166 degrees. The GBM light curve consists of 3 main peaks with a duration of about 60 s with a plateau starting about 20 s before trigger and a tail extending to about 100s after trigger." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14275 SUBJECT: Konus-Wind observation of GRB 130306A DATE: 13/03/08 16:33:09 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 very long-duration GRB 130306A (Swift-BAT trigger #550457: Siegel et al., GCN 14266; Fermi-GBM observation: Pelassa, GCN 14270) triggered Konus-Wind at T0=85669.636s UT (23:47:49.636) The light curve shows a multi-pulse emission which started ~270 s before the trigger, peaked at ~T0+10s, and, after ~T0+110s, passed into a long tail out to ~400 s after the trigger. The total duration of the burst is ~700 s. The emission is seen up to 5 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB130306_T85669/ As observed by Konus-Wind, the burst had a fluence of (2.9 ± 0.05)x10-4 erg/cm2, and a 64-ms peak flux, measured from T0+8.768 s, of (6.1 ± 0.6)x10-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum (measured from T0 to T0+116.224 s) is best fit in the 20 keV - 5 MeV range by a power law with exponential cutoff model, for which: alpha = -1.50 ± 0.05, and Ep = 212 ± 10 keV, chi2 = 53.8/59 dof. The spectrum at the maximum count rate (measured from T0 to T0+11.774 s) is best fit in the 20 keV - 5 MeV range by a power law with exponential cutoff model, for which: alpha = -1.34 ± 0.04, and Ep = 410 ± 30 keV, chi2 = 64.7/71 dof. The spectrum of the emission tail (measured from T0+116.224 to T0+402.944 s) is best fit in the 20 keV - 5 MeV range by the simple power-law model with the photon index -2.3 ± 0.1, chi2 = 65.1/75 dof. The emission in this time interval is seen up to 4 MeV and the 20 keV - 10 MeV energy fluence is (2.7 ± 0.3)x10-5 erg/cm2. All the quoted results are preliminary. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14279 SUBJECT: GRB 130306A: Swift-BAT refined analysis DATE: 13/03/09 01:15:33 GMT FROM: Scott Barthelmy at NASA/GSFC S. D. Barthelmy (GSFC), A. Lien (NASA/GSFC/ORAU). T. Sakamoto (GSFC/UMBC), W. H. Baumgartner (GSFC/UMBC), 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), G. Sato (ISAS), M. H. Siegel (PSU), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team): Using the data set from T-160 to T+963 sec from recent telemetry downlinks, we report further analysis of BAT GRB 130306A (trigger #550457) (Siegel, et al., GCN Circ. 14266). The BAT ground-calculated position is RA, Dec = 279.475, -11.682 deg, which is RA(J2000) = 18h 37m 54.1s Dec(J2000) = -11d 40' 55.0" with an uncertainty of 1.6 arcmin, (radius, sys+stat, 90% containment). The partial coding was 11%. This burst was already active when it came into the BAT FoV during a slew at T-160 sec. There were several peaks until ~T-130 sec, then a long relatively smooth decay out past T+900 sec (when the data ends). The time-averaged spectrum from T-159.5 to T+154.1 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.95 +- 0.05. The 1-sec peak photon flux (during the period of BAT viewing) measured from T-152.73 sec in the 15-150 keV band is 7.3 +- 0.8 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/550457/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14280 SUBJECT: GRB 130306A: MITSuME Ishigakijima upper limits DATE: 13/03/10 08:25:23 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 130306A (Siegel et al., GCNC 14266) 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 2013-03-07 19:28:07 UT (~19.6 h after the burst). We did not find any new point source within the refined BAT error circle (Barthelmy et al., GCNC 14279) in all the three bands. Three sigma upper limits of the OT are listed below. We used GSC2.3(for g' and Rc) and USNO-B1(for Ic) catalog for flux calibration. T0+[day] MID-UT T-EXP[sec] g' Rc Ic ------------------------------------------------------ 0.84918 20:13:51 4560.0 >20.6 >19.5 >18.4 ------------------------------------------------------ T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14287 SUBJECT: GRB 130306A: Swift Detection of a Possible Afterglow DATE: 13/03/11 15:07:32 GMT FROM: Mike Siegel at PSU/Swift MOC GRB 130306A: Swift Detection of a Possible Afterglow M. H. Siegel (PSU), David N. Burrows (PSU) and Dirk Grupe (PSU) report on behalf of the Swift team: On 8 March 2013 the Swift spacecraft performed a delayed observation of the BAT-detected burst GRB 130306A (Siegel et al., GCN 14266), which was also detected by Fermi GBM (Pelassa, GCN 14270) and Konus/Wind (Golenetskii et al., GCN 14275). We have analyzed 5.1 ks of XRT data, from 146 to 163 ks after the Swift/BAT trigger. The data are entirely in photon counting (PC) mode. An X-ray source is detected within the Swift/BAT error circle. The XRT position is RA, Dec = 279.46147, -11.68123 which is equivalent to: RA (J2000) = 18 37 50.75 Dec(J2000) = -11 40 52.4 with an uncertainty of 4.0 arcsec (radius, 90% confidence). We do not detect any fading over the time span of the Swift observations. The Swift/UVOT began settled observations of the field of GRB 130306A 146 ks after the Swift/BAT trigger. No optical afterglow consistent with the XRT position is detected in the initial UVOT exposures. Preliminary 3-sigma upper limit using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag uvw1 145609 162770 4707 >22.2 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.15 in the direction of the burst (Schlegel et al. 1998). Further observations are planned to determine if the source is fading. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14351 SUBJECT: GRB 130306A: Confirmation of the X-ray Afterglow DATE: 13/03/28 17:32:24 GMT FROM: Mike Siegel at PSU/Swift MOC M. H. Siegel (PSU) reports on behalf of the Swift team: Swift performed a follow-up observation of the possible X-ray afterglow of the BAT-detected GRB 130306A (Siegel et al., GCN Circ. 14287). A 5 ks observation took place on 14 March 2013, eight days after the burst. The reported source faded by at least a factor of three, from .009 counts s^-1 (observed flux 4.2 x 10^-13 erg cm^-2 s^-1) to an upper limit of of .003 counts s^-1 (observed flux 1.5 x 10^-13 erg cm^-2 s^-1). We therefore confirm that this was the X-ray afterglow of GRB 130306A.