//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13282 SUBJECT: GRB 120510A: MAXI/GSC detection of a burst DATE: 12/05/10 13:45:36 GMT FROM: Motoko Suzuki at RIKEN N. Serita, H. Negoro, M. Nakajima, M. Asada, H. Sakakibara (Nihon U.), M. Serino, T. Mihara, M. Sugizaki, T. Yamamoto, M. Matsuoka (RIKEN), S. Nakahira, S. Ueno, H. Tomida, M. Ishikawa (JAXA), N. Kawai, M. Morii, R. Usui, K. Ishikawa (Tokyo Tech), A. Yoshida (AGU), H. Tsunemi, M. Kimura (Osaka U.), Y. Ueda, K. Hiroi, M. Shidatsu, R. Sato (Kyoto U.), Y. Tsuboi, M. Higa (Chuo U.) M. Yamauchi, Y. Nishimura, T. Hanayama, K. Yoshidome (Miyazaki U.), K. Yamaoka (Waseda U.) report on behalf of the MAXI team: During a scan transit centered at UT 2012-05-10T08:47:44, MAXI/GSC detected a short X-ray transient lasting about 27 seconds within the 42 seconds triangular transit response of MAXI/GSC. Judging from its hardness ratio, this transient is probably a gamma-ray burst. Assuming that the source flux was constant over the transit, we obtain the source position at (R.A., Dec) = (+44.285 deg, +72.850deg) = ( 02 57 08.60, +72 51 00.8 )(J2000) which has a statistical uncertainty of 10 arcmin at the 90% confidence limit and an additional systematic uncertainty of 6 arcmin (90% containment radius). Due to a short burst duration, the uncertainty for the scan direction is possibly larger than this estimation. Without assuming a constant flux of the source, a rectangular sky region of 90% confidence is 0.4 degrees by 1.4 degrees with the following corners: (R.A., Dec) = (+41.76 deg, +72.60 deg) = (02 47 2, +72 36 12)(J2000) (R.A., Dec) = (+41.77 deg, +73.02 deg) = (02 47 4, +73 01 20)(J2000) (R.A., Dec) = (+46.50 deg, +72.97 deg) = (03 06 0, +72 58 4)(J2000) (R.A., Dec) = (+46.40 deg, +72.55 deg) = (03 05 36, +72 32 59)(J2000). The preliminary flux estimate (4-10 keV) of the source was 330+-40 mCrab. There was no significant detection at the transit location in the previous and the following orbits (92 min before and after the detection) with an upper limit of 20 mCrab. Follow-up observations are encouraged. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13283 SUBJECT: GRB 120510A: MASTER follow up observations DATE: 12/05/11 08:42:15 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov Blagoveschensk Educational State University, Blagoveschensk E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina, N.Shatskiy, P.Balanutsa, D.Zimnukhov, A.Kuznetsov, V.V.Chazov, A.Kuznetsov, A.Sankovich Moscow Lomonosov State University, Sternberg Astronomical Institute, K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk Irkutsk State University A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory V.Krushinski, I.Zalozhnich, A. Popov, A. Bourdanov, A. Punanova Ural Federal University 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 Blagoveschensk was pointed to the 120510A 24146 sec after GRB time at 2012-05-10 15:30:10.64 UT. On our first (180s exposure) set we haven`t found optical transient within MAXI/GSC error-box (Serita et al., GCN Circ 13282). The 5-sigma upper limit has been about 18.6 mag The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13284 SUBJECT: GRB 120510A: Swift XRT and UVOT observations DATE: 12/05/11 14:39:44 GMT FROM: Paolo D'Avanzo at INAF-OAB P. D'Avanzo, A. Melandri (INAF-OAB), K. L. Page, P. A. Evans (U Leicester), M. Perri (ASDC), S. T. Holland (NASA/GSFC) report on behalf of the Swift team: The Swift XRT and UVOT instruments observed the centre of the error circle for the MAXI-detected GRB 120510A (Serita et al., GCN Circ. 13282) from 21.4 to 33.0 ks after the trigger. The XRT data comprise 2.0 ks of Photon Counting (PC) mode data. A faint source is detected RA, Dec = 44.04666, +72.88692 which is equivalent to: RA (J2000): 02h 56m 11.20s Dec (J2000): +72d 53' 12.9" with an uncertainty of 4.8 arcsec (radius, 90% confidence). The observed count rate is (3.3 +/- 1.3) x 10^-3 cts/s. This corresponds to an observed 0.3-10 keV flux of (1.4 +/- 0.5) x 10^-13 erg/cm2/s (assuming a typical GRB spectrum with photon spectral index of 2). If we consider the Galactic absorption in this direction (2.3 x 10^21 cm^-2; Kalberla et al. 2005) this corresponds to an unabsorbed flux of (2.0 +/- 0.8) x 10^-12 erg/cm2/s. Given the limited statistics, it is not possible to determine whether the source is fading. We note that the XRT position lies 15.6 arcsec from the ROSAT source 1RXS J025613.2+725300 (RA(J2000), Dec(J2000)= 02h 56m 13.2s, +72d 52' 59", with an error radius of 11 arcsec). We also note that the XRT field of view covers only about 69% of the reported 16 arcmin radius error circle GRB 120510A (Serita et al., GCN Circ. 13282). The XRT coordinates correspond to the bright, catalogued ultraviolet source HD 17785 with a magnitude of uvw2 = 11.85 +/- 0.02 mag. There is very weak evidence in the UVOT data that the source may have increased in brightness by about 0.2 mag between 28 ks and 33 ks after the burst. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13285 SUBJECT: GRB 120510B/Fermi Trigger 358364818: MASTER possible OT candidate DATE: 12/05/11 17:37:09 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, D.Denisenko, A.Belinski, N.Tyurina, N.Shatskiy, P.Balanutsa, D.Zimnukhov, A.Kuznetsov, V.V.Chazov, A.Kuznetsov Moscow Lomonosov State University, Sternberg Astronomical Institute, A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk Irkutsk State University V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov Blagoveschensk Educational State University, Blagoveschensk V.Krushinski, I.Zalozhnich, A. Popov, A. Bourdanov, A. Punanova Ural Federal University 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 Fermi Trigger 358364818/GRB120510B 36 sec after GRB time at 2012-05-10 17:47:32.938 UT. On our Very Wide Field Camera (400 square degrees, 1 pix = 22 arcsec) set of images we have found optical transient within FERMI error-box with ~10 mag (unfiltered). The OT position is: Ra = 12h 51m 37.9s Dec = +00d 05m 35s with the error box (one sigma) radius equal to 10". We have reference image without OT on 2012-04-21 20:11:39 UT with unfiltered magnitude limit 12.5 m. In the follow up MASTER II Amur observations on 2012-05-11 at 15:12:29 UT there is no OT brighter than 17.2 m. There are two SDSS galaxies inside one sigma error box: SDSS J125138.22+000534.5 (rmag=19.83) and SDSS J125138.45+000534.7 (rmag=21.98) The data reduction is continuing. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13295 SUBJECT: Konus-Wind observation of GRB 120510A DATE: 12/05/14 15:05:19 GMT FROM: Valentin Pal'shin at Ioffe Inst S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind team report: The long GRB 120510A localized by MAXI/GSC (Serita et al., GCN 13282) was detected by Konus-Wind in the waiting mode. The burst light curve shows several pulses with a total duration of ~130 s. As observed by Konus-Wind, the burst had a fluence of (3.82 +/- 0.26)x10^-6 erg/cm2 (in the 20 - 1200 keV energy range). Fitting the K-W 3-channel time-integrated spectrum (from T0(MAXI)+5 s to T0(MAXI)+135 s) by a simple power-law model yields a power law index of 2.05 +/- 0.24. All the quoted errors are estimated at the 1 sigma confidence level. The K-W light curve of this burst is available at http://www.ioffe.rssi.ru/LEA/GRBs/GRB120510A/