//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 27861 SUBJECT: GRB 200530A: Fermi GBM Final Real-time Localization DATE: 20/05/30 00:54:31 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 00:44:10 UT on 30 May 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200530A (trigger 612492255.567684 / 200530031). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 17.3, Dec = 71.9 (J2000 degrees, equivalent to J2000 01h 09m, 71d 54'), with a statistical uncertainty of 2.5 degrees. The angle from the Fermi LAT boresight is 37.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200530031/quicklook/glg_skymap_all_bn200530031.png The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200530031/quicklook/glg_healpix_all_bn200530031.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200530031/quicklook/glg_lc_medres34_bn200530031.gif //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 27862 SUBJECT: Fermi GRB 200530A: Global MASTER-Net observations report DATE: 20/05/30 01:00:16 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva, D.Kuvshinov, D. Cheryasov (Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), H.Levato (Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias), D. Buckley (South African Astronomical Observatory), O.A. Gres, N.M. Budnev, O.Ershova (Irkutsk State University, API), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), V. Yurkov, A. Gabovich, Yu. Sergienko (Blagoveschensk Educational State University) MASTER-IAC robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Spain (IAC Teide Observatory) started inspect of the Fermi GRB 200530A ( Fermi GBM team, GCN 27861) errorbox 592 sec after notice time and 619 sec after trigger time at 2020-05-30 00:54:29 UT, with upper limit up to 16.1 mag. The observations began at zenith distance = 75 deg. The sun altitude is -40.2 deg. The galactic latitude b = 9 deg., longitude l = 125 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1369228 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 679 | 2020-05-30 00:54:29 | MASTER-IAC | (01h 06m 24.58s , +71d 45m 48.9s) | P| | 120 | 16.1 | The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 27864 SUBJECT: GRB 200530A: AstroSat CZTI detection DATE: 20/05/30 11:18:25 GMT FROM: Soumya Gupta at IUCAA/ASTROSAT S. Gupta, V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (IUCAA/TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration: Analysis of AstroSat CZTI data showed the detection of a long GRB 200530A, which was also detected by Fermi GBM (GCN #27861) and Global MASTER-Net (Lipunov V. et al., GCN # 27862). The source was clearly detected in the 40-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2020-05-30 00:44:20.150 UT. The measured peak count rate associated with the burst is 669 +/- 29 cts/s above the background in the combined data of four quadrants, with a total of 8172 +/- 74 cts. The local mean background count rate was 498 +/- 2 cts/s. Using cumulative rates, we measure a T90 of 20.98 +/- 0.08 s. In preliminary analysis, we find that 605 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. The light curve showed multiple peaks of emission with the strongest peak at 2020-05-30 00:44:19.000 UT. The measured peak count rate is 709 +/- 46 cts/s above the background in the combined Veto data of four quadrants, with a total of 5449 +/- 134 cts. The local mean background count rate was 1431 +/- 3 cts/s. We measure a T90 of 20.87 +/- 0.31 s from the cumulative Veto light curve. 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. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 27891 SUBJECT: GRB 200530A: Fermi-LAT detection DATE: 20/06/05 18:03:00 GMT FROM: Francesco Longo at U of Trieste,INFN Trieste F. Longo (University and INFN, Trieste), D. Kocevski (NASA/MSFC), N. Di Lalla (Stanford University), M. Ohno (Hiroshima Univ.), F. Fana Dirirsa (Univ. of Johannesburg), N. Omodei (Stanford University) and J. Racusin (NASA/GSFC) report on behalf of the Fermi-LAT Collaboration: On May 30, 2020, Fermi-LAT detected high-energy emission from GRB 200530A, which was also detected by Fermi-GBM at T0 = 00:44:10 UT (GCN 27861). The GRB is detected at high energy (>100 MeV) by Fermi-LAT at a location of: RA, Dec = 32.1, 69.2 (degrees, J2000) with an error radius of 0.5 deg (90% containment, statistical error only). This was ~40 deg from the LAT boresight when observations started, and is ~6 deg from the GBM final ground position. The photon flux above 100 MeV in the time interval 0 - 1000 s after the GBM trigger is 5.5 e-06 +/- 1.8 e-06 ph/cm2/s. The estimated photon index above 100 MeV is -2.3 +/- 0.3. The highest-energy photon is a 1.6 GeV event which is observed ~100 seconds after the GBM trigger. After ~T0+1000 s, the GRB location moved outside the LAT FoV. When it re-entered in the LAT FoV at later times (from ~4800 to ~6700 s) it was not detected. The late time notification of this detection is due to a delay on the data processing for the data of May 30. The Fermi-LAT point of contact for this burst is Francesco Longo (francesco.longo@ts.infn.it). The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 27896 SUBJECT: GRB 200530A: CALET Gamma-Ray Burst Monitor detection DATE: 20/06/06 12:01:09 GMT FROM: Valentin Pal'shin at AGU S. Sugita, A. Yoshida, T. Sakamoto, V. Pal'shin (AGU), Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), Y. Asaoka, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC), M. L. Cherry (LSU), S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena), and the CALET collaboration: The long GRB 200530A (Fermi GBM Localization: the Fermi GBM team, GCN Circ. 27861; AstroSat CZTI detection: Gupta et al., GCN Circ. 27864; Fermi-LAT detection: Longo et al., GCN Circ. 27891; https://gcn.gsfc.nasa.gov/other/200530A.gcn3) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 00:44:15.067 UTC on 30 May 2020. The burst signal was seen by all CGBM detectors. Because of a problem in one of the ground alert processing script, the GCN notice was not distributed automatically for this event. The burst light curve shows a multi-peaked structure which starts at T-2.9 sec, peaks at T+5.6 sec and ends at T+21.1 sec. The T90 and T50 durations measured by the SGM data are 19.7 +- 2.0 sec and 9.5 +- 0.9 sec (40-1000 keV), respectively. The ground processed light curve is available at http://cgbm.calet.jp/cgbm_trigger/ground/1274834660/ The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at the Waseda University. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 27897 SUBJECT: GRB 200530A: Fermi GBM detection DATE: 20/06/06 23:30:30 GMT FROM: Joshua Wood at MSFC/Fermi-GBM J. Wood (NASA/MSFC) and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 00:44:10.57 UT on 30 May 2020, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 200530A (trigger 612492255 / GBM200530031), which was also detected by the Fermi/LAT (Longo et al. 2020, GCN 27891) The Fermi GBM Final Real-time Localization is consistent with the LAT position. The angle from the Fermi LAT boresight at the GBM trigger time is 41 degrees. The GBM light curve shows a multi-peaked structure with a duration (T90) of about 23 s (50-300 keV). The time-averaged spectrum from T0-1.5 s to T0+28.2 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.55 +/- 0.02 and the cutoff energy, parameterized as Epeak, is 178 +/- 4 keV. The event fluence (10-1000 keV) in this time interval is (2.27 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+10.0 s in the 10-1000 keV band is 10.9 +/- 0.3 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog: https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html For Fermi GBM data and info, please visit the official Fermi GBM Support Page: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"