//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10358 SUBJECT: GRB 100131A: Fermi GBM detection DATE: 10/02/02 06:00:26 GMT FROM: Adam Goldstein at Fermi-GBM/UAH A. Goldstein (UAH) reports on behalf of the Fermi GBM Team: "At 17:30:57.67 UT on 31 January 2010, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 100131A (trigger 286651859 / 100131730). The Fermi Observatory executed a maneuver following this trigger and tracked the burst location for the next 5 hours, subject to Earth-angle constraints. The on-ground calculated location, using the GBM trigger data, is RA = 120.4, DEC = +16.5 (J2000 degrees, equivalent to 08h 02m, 16d 29'), with an uncertainty of 1.2 degrees (radius, 1-sigma containment, statistical only; there is additionally a systematic error which is currently estimated to be 2 to 3 degrees). The angle from the Fermi LAT boresight was 27 degrees. This burst was also independently detected by INTEGRAL SPI-ACS. The GBM light curve consists of a single bright spike with substructure with a duration (T90) of about 6.2 s (8-1000 keV). The time-averaged spectrum from T0 to T0+4.5 s is best fit by a Band function with Epeak = 132.10 +/- 6.28 keV, alpha = -0.63 +/- 0.05, and beta = -2.21 +/- 0.05 (Castor C statistic of 413 for 360 d.o.f.). The event fluence (8-1000 keV) in this time interval is (7.723 +/- 0.130)E-06 erg/cm^2. The 0.128-sec peak photon flux measured starting from T0 in the 8-1000 keV band is 33.8 +/- 1.5 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: 10363 SUBJECT: GRB 100131A: Suzaku WAM observation of the prompt emission DATE: 10/02/05 06:03:29 GMT FROM: Yusuke Nishioka at Miyazaki U. Y. Nishioka, H. Hayashi, N. Ohmori, A. Daikyuji, E. Sonoda, K. Kono, K. Noda, M. Yamauchi (Univ. of Miyazaki), T. Sugasahara, M. Tashiro, Y. Terada, A. Endo, K. Onda, W. Iwakiri (Saitama U.), S. Sugita (Nagoya U.), K. Yamaoka (Aoyama Gakuin U.), M. Ohno, M. Suzuki, M. Kokubun, T. Takahashi (ISAS/JAXA), Y. E. Nakagawa, T. Tamagawa (RIKEN), N. Vasquez (Tokyo Tech.), Y. Urata, H.M Lin (NCU), Y. Hanabata, T. Uehara, T. Takahashi, Y. Fukazawa (Hiroshima U.), T. Enoto, K. Nakazawa, K. Makishima (Univ. of Tokyo), S. Hong (Nihon U.), on behalf of the Suzaku WAM team, report The long GRB 100131A (Fermi/GBM trigger #286651859 ; A. Goldstein et al., GCN 10358) triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV on 2010-01-31 17:30:58.052 UT (=T0). The observed light curve shows a multi-peaked structure lasting from T0-0.5s to T0+2s, followed by a weaker emission seen up to T0+4s with a duration (T90) of about 3.2 seconds. The fluence in 100 - 1000 keV was 2.72(-0.41, +0.30) x10^-6 erg/cm^2. The 1-s peak flux measured from T0 s was 4.52(-0.80, +0.57) photons/cm^2/s in the same energy range. Preliminary result shows that the time-averaged spectrum from T0-0.5s to T0+5.5s is well fitted by a single power-law with a photon index of 2.62 (-0.37, +0.44) (chi^2/d.o.f = 11.8/13). All the quoted errors are at statistical 90% confidence level, in which the systematic uncertainties are not included. The light curves for this burst are available at: http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10393 SUBJECT: GRB 100131A: MASTER-Net optical alert observations DATE: 10/02/07 13:47:58 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V.Yurkov, S.Sergienko Blagoveschensk Educational State University, Blagoveschensk E. Gorbovskoy, V. Lipunov, V.Kornilov, A.Belinski, N.Shatskiy, N.Tyurina, D.Kuvshinov, P.Balanutsa, V.V.Chazov, P.V.Kortunov, A.Kuznetsov, D.Zemnukhov, M. Kornilov Sternberg Astronomical Institute, Moscow State University A. Tlatov, A.V. Parhomenko, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory V.Krushinski, I.Zalozhnih, T.Kopytova, A. Popov Ural State University, Kourovka K.Ivanov, S.Yazev, N.M.Budnev, E.Konstantinov, V.Lenok Irkutsk State University MASTER robotic telescope (MASTER-Net: http://observ.pereplet.ru, 200 mm, FOV=8 square degrees (testing mode)) and Very Wide Field Camera (D=50 mm, 1000 square degrees, 11 Mpx, 36" per pix, mounted on telescope) located at Blagoveschensk was responted to the GRB 100131A (Fermi GBM alert, Goldstein et al, GCN CIRC 10358) 76 sec after first Notice time and 93 s after the GRB time. The center FOV of the main telescope correspond to first alert imformation: RA=107.420+-3 DEC=+3.730+-3 The limit of the main telescope images is aboute 15 mag (unfiltered). We have a number images with 5 s exposition from Very Wide Field Camera. The image limit from Very Wide Filed Camera ~10 mag. There is now OT in our images inside Fermi error box (A. Goldstein, GCN CIRC 10358) brighter 10 mag. The imege is available at http://observ.pereplet.ru/images/GRB100131A/grb100131A.jpg . The circles correspond to 1sigma + systematic Fermi error box, and 3sigma+systematic error box. The message may be cited. mailto: lipunov@sai.msu.ru