//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18291 SUBJECT: GRB 150912A: A long GRB detected by INTEGRAL DATE: 15/09/12 11:39:08 GMT FROM: Sandro Mereghetti at IASF/CNR S.Mereghetti (IASF-Milano), D.Gotz (CEA, Saclay), E.Bozzo, C.Ferrigno, L.Ducci (ISDC, Versoix), and J.Borkowski (CAMK, Torun) on behalf of the IBAS Localization Team report: a gamma ray burst lasting about 30 s has been detected by IBAS in the IBIS/ISGRI data at 10:37:30 UT of 2015 September 12. The refined coordinates (J2000) are: R.A.= 248.4435 deg DEC.= -21.03376 deg with an uncertainty of 2 arcmin (90% c.l.). The burst had a peak flux of about 1.5 counts/cm2/s (20-200 keV, 1-s integration time) and a fluence in the same energy range of about 1e-6 erg/cmq. A plot of the light curve will be posted at http://ibas.iasf-milano.inaf.it/IBAS_Results.html //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18297 SUBJECT: GRB 150912A: Swift ToO observations DATE: 15/09/12 19:40:14 GMT FROM: Phil Evans at U of Leicester P. A. Evans (U. Leicester) reports on behalf of the Swift team: Swift has initiated a ToO observation of the INTEGRAL GRB 150912A. Automated analysis of the XRT data will be presented online at http://www.swift.ac.uk/ToO_GRBs/00020557 Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. These are not necessarily related to the INTEGRAL event. Any X-ray source considered to be a probable afterglow candidate will be reported via a GCN Circular after manual consideration. Details of the XRT automated analysis methods are detailed in Evans et al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8). This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18299 SUBJECT: GRB 150912A: Fermi GBM observation DATE: 15/09/12 21:34:34 GMT FROM: Elisabetta Bissaldi at U.Innsbruk/IAPP E. Bissaldi (INFN Bari) reports on behalf of the Fermi GBM Team: "At 10:37:38.70 UT on 12 September 2015, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 150912A (trigger 463747062/150912443), which was also detected by INTEGRAL (Mereghetti et al. 2015, GCN 18291). The GBM on-ground location is consistent with the INTEGRAL position. The angle from the Fermi-LAT boresight at the GBM trigger time is 67 degrees. The GBM light curve consists of a single peak with a duration (T90) of about 30 s (50-300 keV). The time-averaged spectrum from T0-6 s to T0+22 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.11 +/- 0.10 and the cutoff energy, parameterized as Epeak, is 250 +/- 40 keV. The event fluence (10-1000 keV) in this time interval is (4.5 +/- 0.3)E-06 erg/cm^2. The 1-sec peak photon flux, measured starting from T0+2.2 s in the 10-1000 keV band, is 2.82 +/- 0.25 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: 18300 SUBJECT: GRB 150912A: MASTER-IAC optical observations DATE: 15/09/12 22:30:37 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias V. Lipunov, E. Gorbovskoy, N.Tyurina, V.Kornilov, P.Balanutsa, A.Kuznetsov, D.Kuvshinov, E.Popova Lomonosov Moscow State University, Sternberg Astronomical Institute K.Ivanov, O.Gres, N.M.Budnev, S.Yazev, Irkutsk State University D.Buckley, S. Potter, A.Kniazev, M.Kotze South African Astronomical Observatory A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov, A.Gabovich Blagoveschensk Educational State University, Blagoveschensk V.Krushinski, I.Zalozhnih 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 IAC was pointed to the GRB150912A 33865 sec (9.4 h) after trigger time at 2015-09-12 20:01:55 UT directly after the sunset. On our first single and coadd sets we haven`t found optical transient within IPN error-box (Mereghetti et. al GCN 18291). The 5-sigma upper limit has been about 19.2 on single (180 sec) and ~ 20.3 at coadd (10x180 sec) images. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18304 SUBJECT: GRB 150912A: MITSuME Ishigakijima upper limits DATE: 15/09/14 00:44:10 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 and OISTER collaboration: We observed the field of GRB 150912A (Mereghetti et al., GCNC 18291) 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 2015-09-12 12:15:39 UT (~1.6 h after the burst). We did not find any new point source within the INTEGRAL-IBAS error circle (Mereghetti et al., GCNC 18291) 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 ----------------------------------------------------- 0.07014 12:18:30 300.0 >19.7 >19.4 >18.6 ----------------------------------------------------- T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18310 SUBJECT: GRB 150912A: Swift-XRT and UVOT observations DATE: 15/09/14 13:38:28 GMT FROM: Kim Page at U.of Leicester K.L. Page (U. Leicester), M. H. Siegel (PSU) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the INTEGRAL-detected burst GRB 150912A (Mereghetti et al. GCN Circ. 18291), collecting 4.7 ks of Photon Counting (PC) mode data between T0+32.6 ks and T0+50.4 ks. No X-ray sources have been detected inside or close to the INTEGRAL error region. The 3-sigma upper limit in the field ranges from ~0.002 to ~0.004 ct s^-1, corresponding to a 0.3-10 keV observed flux of 9.0e-14 to 1.5e-13 erg cm^-2 s^-1 (assuming a typical GRB spectrum). Two uncatalogued sources were detected too far from the GRB position to be likely afterglow candidates. The results of the XRT-team automatic analysis of the XRT observations, including a position-specific upper limit calculator, are available at http://www.swift.ac.uk/ToO_GRBs/00020557. Swift-UVOT also began settled observations of the field of GRB 150912A 32.6 ks after the INTEGRAL trigger. No optical afterglow consistent with the INTEGRAL position 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 initial exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag w2 32643 50446 4789 >21.2 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.42 in the direction of the burst (Schlegel et al. 1998). This circular is an official product of the Swift-XRT and UVOT teams.