//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23025 SUBJECT: GRB 180723.76: MASTER optical observation of the bright long Fermi GBM trigger number 554062193 DATE: 18/07/24 08:17:49 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs E. Gorbovskoy, V.Lipunov, N.Tiurina, V.Kornilov, A.Kuznetsov, V.Chazov, I. Gorbunov, D.Zimnukhov, D.Kuvshinov, P.Balanutsa, V.Vladimirov, D.Vlasenko, Lomonosov Moscow State University,SAI D.Svinkin Ioffe Institute, Sankt Petersburg D. Buckley, South African Astronomical Observatory (SAAO) R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias (IAC) A. Tlatov, V.Senik, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory R. Podesta, F. Podesta, C. Lopez, C.Francile Observatorio Astronomico Felix Aguilar (OAFA) H.Levato, Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE) O. Gres, N.M.Budnev , Yu.Ishmuhametova Irkutsk State University (ISU) A. Gabovich, V. Yurkov, Yu. Sergienko Blagoveschensk Educational State University (BSPU) MASTER-SAAO robotic telescope (MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) was pointed to the GRB180723.76 198 sec after notice time and 767 sec after trigger time at 2018-07-23 18:22:35 UT (see Fermi GBM trgger number 554062193). On our first (150s exposure) set we haven`t found optical transient within FERMI error-box (ra=7.83333 dec=-66.1097 r=1). The 5-sigma upper limit has been about 17.5 mag There is no OT brighter 19.2 mag found on stacked images. The coverage map of the 3 sigms + sigma error box is available at http://master.sai.msu.ru/static/OT/MASTERSAAOmapFermi554062193.jpg The observations made on zenit distance = 74 degrees under strong wind, galaxy latitude b = -51 degree. The moon (86 % bright part) is 69 degrees above the horizon. The distance between moon and object is 82 The sun altitude is -31.3 degree. The object observed till sunrise at 2018-07-24 05:30:53 UT. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23027 SUBJECT: GRB 180723.13: MASTER optical observation of the short Fermi GBM trigger number 554008254 DATE: 18/07/24 10:31:46 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V.Lipunov, E. Gorbovskoy, N.Tiurina, V.Kornilov, A.Kuznetsov, V.Chazov, I. Gorbunov, D.Zimnukhov, D.Kuvshinov, P.Balanutsa, V.Vladimirov, D.Vlasenko, Lomonosov Moscow State University,SAI D.Svinkin Ioffe Institute, StPetersburg D. Buckley, South African Astronomical Observatory (SAAO) R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias (IAC) A. Tlatov, V.Senik, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory R. Podesta, F. Podesta, C. Lopez, C.Francile Observatorio Astronomico Felix Aguilar (OAFA) H.Levato, Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE) O. Gres, N.M.Budnev , Yu.Ishmuhametova Irkutsk State University (ISU) A. Gabovich, V. Yurkov, Yu. Sergienko Blagoveschensk Educational State University (BSPU) MASTER-OAFA robotic telescope (MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) was pointed to the GRB180723.13 45 sec after notice time and 90 sec after trigger time at 2018-07-23 03:12:19 UT. On our first (20s exposure) set we not found optical transient within FERMI error-box (ra=136.058 dec=-64.17 r=4.29) brighter then 15.8. The coverage map of the 3 sigms + sigma error box is available at http://master.sai.msu.ru/static/OT/MASTERmapFermi554008254.jpg The observations made on zenit distance = 80 degrees, galaxy latitude b = -11 degree. The moon (81 % bright part) is 58 degrees above the horizon. The distance between moon and object is 83 The sun altitude is -66.7 degree. The object can be observed till sunrise at 2018-07-23 11:31:04 UT. MASTER-OAFA robotic telescope was pointed for second inspection to the GRB180723.13 1 days 20938 sec after notice time and 1 days 20938 sec after trigger time at 2018-07-24 08:59:48 UT. We not found OT brighter then 18.1. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23029 SUBJECT: GRB 180723A: CALET Gamma-Ray Burst Monitor detection DATE: 18/07/24 11:09:44 GMT FROM: Takanori Sakamoto at AGU W. Ishizaki (ICRR), A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita, Y. Kawakubo, A. Tezuka, S. Matsukawa, H. Onozawa, T. Ito, H. Morita, Y. Sone (AGU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), I. Takahashi (IPMU), Y. Asaoka, S. Ozawa, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), M. L. Cherry (LSU), S. Ricciarini (U of Florence), A. V. Penacchioni, P. S. Marrocchesi (U of Siena) and the CALET collaboration: The long GRB 180723A (Fermi-GBM trigger #554062193) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 18:09:45.493 UTC on 23 July 2018. This GRB is also clearly seen by the publicly available INTEGRAL SPI-ACS light curve. The burst signal was seen by all CGBM detectors. The burst light curve shows a FRED-like pulse which starts at T+2.4 sec, peaks at T+4.9 sec, and ends at T+14.5 sec. The T90 and the T50 durations measured by the SGM data are 10.0 +- 1.3 sec and 4.3 +- 0.7 sec (40-1000 keV), respectively. The ground processed light curve is available at http://cgbm.calet.jp/cgbm_trigger/ground/1216404464/ The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at the Waseda University. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23035 SUBJECT: GRB 180723A: Fermi GBM detection DATE: 18/07/25 02:37:32 GMT FROM: Suraj Poolakkil at UAH S.Poolakkil and C. Meegan (both UAH) report on behalf of the Fermi GBM Team: "At 18:09:48.16 UT on 23 July 2018, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 180723A (trigger 554062193/ 180723757). The on-ground calculated location, using the GBM trigger data, is RA = 7.84, DEC = -66.11, with an uncertainty of 1 degree (radius, 1-sigma containment, statistical only; there is additionally a systematic error which we have characterized as a core-plus-tail model, with 90% of GRBs having a 3.7 deg error and a small tail suffering a larger than 10 deg systematic error. [Connaughton et al. 2015, ApJS, 216, 32] ). The angle from the Fermi LAT boresight at the GBM trigger time is 132 degrees. The GBM light curve consists of a single bright peak with a duration (T90) of about 19.71 s (50-300 keV). The time-averaged spectrum from T0-2.05 s to T0+31.74 s is best fit by a power-law function with an exponential high-energy cutoff. The power law index is -1.22 +/- 0.02 and the cutoff energy, parameterized as Epeak, is 178 +/- 5 keV. The event fluence (10-1000 keV) in this time interval is (4.616 +/- 0.057)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+3.39 s in the 10-1000 keV band is 41.2 +/- 0.81 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: 23099 SUBJECT: GRB 180723A: AstroSat CZTI detection DATE: 18/08/08 07:57:10 GMT FROM: Vidushi Sharma at IUCAA V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the Astrosat CZTI collaboration: Analysis of Astrosat CZTI data showed the detection of a bright GRB 180723A, which was also detected by CALET (Ishizaki W. et al., GCN 23029) and Fermi-GBM (Poolakkil S. et al., GCN 23035). The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with strongest peak at 18:09:49.50 UT. The measured peak count rate is 1123.5 cts/s above the background in combined data of four quadrants, with a total of 6717 cts. The local mean background count rate was 543.5 cts/s. Using cumulative rates, we measure a T90 of 25.3 s. In preliminary analysis, we find that 459 compton events are associated with this event. It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.