//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 33420 SUBJECT: GRB 230308A: Fermi GBM Final Real-time Localization DATE: 23/03/08 13:42:49 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely SHORT GRB At 13:32:27 UT on 8 Mar 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230308A (trigger 699975152.401482 / 230308564). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 94.9, Dec = 68.5 (J2000 degrees, equivalent to J2000 06h 19m, 68d 30'), with a statistical uncertainty of 1.2 degrees. The angle from the Fermi LAT boresight is 42.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230308564/quicklook/glg_skymap_all_bn230308564.png The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230308564/quicklook/glg_healpix_all_bn230308564.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230308564/quicklook/glg_lc_medres34_bn230308564.gif //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 33421 SUBJECT: GRB 230308A: BALROG localization (Fermi Trigger 699975152 / GRB 230308564) DATE: 23/03/08 14:14:58 GMT FROM: Jochen Greiner at MPE,Garching F. Kunzweiler, B. Biltzinger, F. Berlato, J. Burgess & J. Greiner (all MPE Garching) report: The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger 699975152 at 13:32:27 on 08 March 2023 were automatically fitted for spectrum and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427; Berlato et al. 2019, ApJ 873, 60). The best-fit position (1 sigma statistical errors) is: RA(2000.0) = 104.5+/-7.6 deg Decl.(2000.0) = 67.3+/-1.3 deg We estimate an additional systematic error of 2 deg. Further details are available at: https://grb.mpe.mpg.de/grb/GRB230308564/ The Healpix map can be downloaded from: https://grb.mpe.mpg.de/grb/GRB230308564/healpix The location parameters are available as JSON at: https://grb.mpe.mpg.de/grb/GRB230308564/json //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 33422 SUBJECT: Fermi GRB 230308A: Global MASTER-Net observations report DATE: 23/03/08 14:45:25 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D.Cheryasov, Ya.Kechin (Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias), D. Buckley (South African Astronomical Observatory), O.A. Gres, N.M. Budnev (Irkutsk State University, API), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational State University) MASTER-Amur robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Blagoveshchensk State Pedagogical University) started inspect of the Fermi GRB 230308A ( Fermi GBM team, GCN 33420) errorbox 425 sec after notice time and 433 sec after trigger time at 2023-03-08 13:39:40 UT, with upper limit up to 13.7 mag. The observations began at zenith distance = 25 deg. The sun altitude is -38.2 deg. The galactic latitude b = 23 deg., longitude l = 146 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2202835 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 463 | 2023-03-08 13:39:40 | MASTER-Amur | (06h 45m 46.77s , +67d 45m 57.7s) | C | 60 | 13.1 | 653 | 2023-03-08 13:42:19 | MASTER-Amur | (06h 43m 52.37s , +68d 29m 21.6s) | C | 120 | 13.4 | 802 | 2023-03-08 13:44:39 | MASTER-Amur | (06h 43m 58.56s , +68d 29m 42.6s) | C | 140 | 13.6 | 981 | 2023-03-08 13:47:18 | MASTER-Amur | (06h 44m 00.51s , +68d 31m 15.4s) | C | 180 | 13.7 | 1181 | 2023-03-08 13:50:38 | MASTER-Amur | (06h 43m 59.72s , +68d 29m 55.5s) | C | 180 | 13.3 | 1381 | 2023-03-08 13:53:58 | MASTER-Amur | (06h 44m 02.77s , +68d 31m 44.3s) | C | 180 | 13.0 | 1581 | 2023-03-08 13:57:18 | MASTER-Amur | (06h 43m 56.37s , +68d 30m 49.1s) | C | 180 | 13.0 | 1780 | 2023-03-08 14:00:37 | MASTER-Amur | (06h 43m 57.85s , +68d 31m 51.9s) | C | 180 | 12.9 | 2325 | 2023-03-08 14:10:42 | MASTER-Amur | (06h 45m 57.98s , +67d 44m 51.0s) | C | 60 | 12.5 | 2644 | 2023-03-08 14:16:01 | MASTER-Amur | (06h 05m 57.43s , +67d 46m 12.0s) | C | 60 | 12.0 | 2724 | 2023-03-08 14:17:21 | MASTER-Amur | (06h 26m 53.34s , +67d 44m 35.3s) | C | 60 | 12.2 | 2803 | 2023-03-08 14:18:40 | MASTER-Amur | (06h 16m 37.96s , +65d 52m 26.5s) | C | 60 | 12.5 | 2883 | 2023-03-08 14:20:00 | MASTER-Amur | (06h 36m 08.13s , +65d 51m 18.8s) | C | 60 | 13.0 | 2963 | 2023-03-08 14:21:20 | MASTER-Amur | (05h 53m 35.35s , +69d 41m 13.3s) | C | 60 | 11.9 | 3042 | 2023-03-08 14:22:39 | MASTER-Amur | (06h 16m 33.34s , +69d 40m 49.4s) | C | 60 | 12.2 | 3122 | 2023-03-08 14:23:59 | MASTER-Amur | (06h 27m 12.11s , +71d 32m 52.6s) | C | 60 | 12.0 | 3776 | 2023-03-08 14:34:53 | MASTER-Amur | (06h 16m 33.48s , +65d 51m 08.9s) | C | 60 | 12.0 | 3856 | 2023-03-08 14:36:13 | MASTER-Amur | (06h 36m 15.00s , +65d 51m 27.1s) | C | 60 | 12.6 | 3936 | 2023-03-08 14:37:32 | MASTER-Amur | (05h 53m 40.42s , +69d 41m 35.5s) | C | 60 | 12.6 | 4016 | 2023-03-08 14:38:52 | MASTER-Amur | (06h 16m 33.80s , +69d 40m 05.9s) | C | 60 | 13.2 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 33435 SUBJECT: GRB 230308A: AGILE/MCAL detection DATE: 23/03/09 10:09:30 GMT FROM: Claudio Casentini at INAF-IAPS C. Casentini (INAF/IAPS), F. Verrecchia (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS and Uni. Roma Tor Vergata), C. Pittori, F. Lucarelli, F. Verrecchia (SSDC, and INAF/OAR), A. Argan, M. Cardillo, Y. Evangelista, L. Foffano, G. Piano (INAF/IAPS), A. Addis, L. Baroncelli, A. Bulgarelli, A. Di Piano, V. Fioretti, G. Panebianco, N. Parmiggiani (INAF/OAS-Bologna), M. Romani (INAF/OA-Brera), M. Marisaldi (INAF/OAS-Bologna, Bergen University), M. Pilia, A. Trois (INAF/OA Cagliari), I. Donnarumma, E. Menegoni, A.Ursi (ASI), A. Giuliani (INAF/IASF-Mi) and P. Tempesta (TeleSpazio), report on behalf of the AGILE Team: The AGILE satellite detected the short GRB 2300308A at T0 = 2023-03-08 13:32:27.400 (UTC), reported by Fermi/GBM (GCN #33420) and BALROG (GCN #33421). The burst is clearly visible in the AGILE scientific ratemeters of the MiniCALorimeter (MCAL; 0.4-100 MeV), and in all the panels of the AntiCoincidence detectors (AC Top, 50-200 keV, ACLat, 80-200 keV). The event lasted about 1 s and it released a total number of 1166 counts in the MCAL detector (above a background rate of 576 Hz), and 7526 counts in the AC Top detector (above a background rate of 3445 Hz). The AGILE ratemeters light curves can be found at: http://www.agilescienceapp.it/notices/GRB230308A_AGILE_RM_ND.png . The event also triggered a high-time resolution MCAL data acquisition, from T0 to T0+12 s (UTC), and released 1484 counts in the detector, above a background rate of 590 Hz. The MCAL light curve can be found at: http://www.agilescienceapp.it/notices/GRB230308A_082579_605367147.400000.png . At the T0 the event was 133 deg off-axis. Additional analysis of AGILE data is in progress. Automatic MCAL GRB alert Notices can be found at: https://gcn.gsfc.nasa.gov/agile_mcal.html //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 33440 SUBJECT: GRB 230308A: Fermi GBM detection DATE: 23/03/09 15:35:20 GMT FROM: Oliver J Roberts at USRA/NASA C. Malacaria (ISSI) reports on behalf of the Fermi GBM Team: "At 13:32:27.40 UT on 8 March 2023, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 230308A (trigger 699975152 / 230308564). The Fermi GBM Final Real-time Localization was reported in GCN 33420. The angle from the Fermi LAT boresight at the GBM trigger time is 42 degrees. The GBM light curve consists of a slightly structured main peak with a duration (T90) of about 0.6 s (50-300 keV). The time-averaged spectrum from T0-0.064 s to T0+0.64 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.52 +/- 0.03 and the cutoff energy, parameterized as Epeak, is 943 +/- 46 keV. A Band function fits the spectrum equally well with Epeak= 907 +/- 52 keV, alpha = -0.51 +/- 0.03, beta = -3.1 +/- 0.4 . The event fluence (10-1000 keV) in this time interval is (8.5 +/- 0.2)E-06 erg/cm^2. The 0.064-sec peak photon flux measured starting from T0 in the 10-1000 keV band is 72 +/- 2 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/" //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 33452 SUBJECT: GRB 230308A: CALET Gamma-Ray Burst Monitor detection DATE: 23/03/11 10:29:09 GMT FROM: Yuta Kawakubo at Louisiana State U./CALET Y. Shimizu (Kanagawa U), A. Yoshida, T. Sakamoto, S. Sugita (AGU), Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), Y. Asaoka (ICRR), S. Torii, Y. Akaike, K. Kobayashi (Waseda U), 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 short GRB 230308A (Fermi GBM Final Real-time Localization: Fermi GBM team, GCN Circ. 33420; BALROG localization: Kunzweiler et al., GCN Circ 33421; AGILE/MCAL detection: Casentini et al., GCN Circ 33435; Fermi GBM detection: Malacaria et al., GCN Circ 33440) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 13:32:27.34 UTC on 8 March 2023 (http://cgbm.calet.jp/cgbm_trigger/flight/1362317395/index.html). The burst signal was seen by all CGBM detectors. The burst light curve shows a multi-peaked structure that starts at T+0.04 sec, peaks at T+0.21 sec, and ends at T+0.37 sec. The T90 and T50 durations measured by the SGM data are 0.29 +/- 0.04 sec and 0.17 +/- 0.04 sec (40-1000 keV), respectively. The ground-processed light curve is available at http://cgbm.calet.jp/cgbm_trigger/ground/1362317395/ The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at Waseda University. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 33477 SUBJECT: IPN triangulation of GRB 230308A (short/bright) DATE: 23/03/14 19:42:15 GMT FROM: Dmitry Svinkin at Ioffe Institute A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin on behalf of the MGNS/BepiColombo and HEND/Mars Odyssey teams, J. Benkhoff on behalf of the BepiColombo team, D. Svinkin, D. Frederiks, A. Ridnaia, A. Lysenko, and T. Cline on behalf of the Konus-Wind team, A. Goldstein, M. S. Briggs, C. Wilson-Hodge, and E. Burns on behalf of the Fermi GBM team, E. Bozzo and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, and W. Boynton, C. Fellows, K. Harshman, H. Enos, R. Starr, and A.S. Gardner on on behalf of the GRS-Odyssey GRB team, report: The bright, short-duration GRB 230308A (Fermi-GBM detection: the Fermi GBM team, GCN Circ. 33420; Malacaria et al., GCN Circ. 33440; BALROG localization: Kunzweiler et al., GCN Circ. 33421; AGILE-MCAL detection: Casentini et al., GCN Circ. 33435) was detected by Fermi(GBM trigger 699975152), Konus-Wind, INTEGRAL (SPI-ACS), AGILE (MCAL), Mars-Odyssey (HEND), and BepiColombo (MGNS) at about 48747 s UT (13:32:27). We have triangulated it to a preliminary, 3 sigma error box whose coordinates are: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Center: 96.381 (06h 25m 31s) +66.621 (+66d 37' 17") Corners: 96.568 (06h 26m 16s) +66.648 (+66d 38' 51") 96.345 (06h 25m 23s) +66.681 (+66d 40' 53") 96.194 (06h 24m 47s) +66.595 (+66d 35' 42") 96.417 (06h 25m 40s) +66.562 (+66d 33' 42") --------------------------------------------- The error box area is 35 sq. arcmin, and its maximum dimension is 9 arcmin (the minimum one is 6.1 arcmin). The Sun distance was 101 deg. This box may be improved. The IPN localization is consistent with, but reduces the area of, the Fermi-GBM final localization (GCN 33420) and the BALROG localization (GCN 33421). A triangulation map and HEALPix FITS file are posted at http://www.ioffe.ru/LEA/GRBs/GRB230308_T48747/IPN/ The Konus-Wind time history and spectrum will be given in a forthcoming GCN Circular. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 33510 SUBJECT: Konus-Wind detection of GRB 230308A DATE: 23/03/23 13:12:16 GMT FROM: Dmitry Svinkin at Ioffe Institute D. Svinkin, D. Frederiks, M. Ulanov, A. Tsvetkova, A. Lysenko, A. Ridnaia, and T. Cline on behalf of the Konus-Wind team, report: The short-duration GRB 230308A (Fermi-GBM detection: the Fermi GBM team, GCN Circ. 33420; Malacaria et al., GCN Circ. 33440; BALROG localization: Kunzweiler et al., GCN Circ. 33421; AGILE-MCAL detection: Casentini et al., GCN Circ. 33435; CALET-GBM detection: Shimizu et al., GCN Circ. 33452; IPN triangulation: Kozyrev et al., GCN Circ. 33477) triggered Konus-Wind at T0=48749.809 s UT (13:32:29.809). The burst light curve shows a multi-peaked structure which starts at ~T0 and has a total duration of ~0.6 s. The emission is seen up to ~4 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB230308_T48749/ As observed by Konus-Wind, the burst had a fluence of 1.31(-0.14,+0.16)x10^-5 erg/cm2, and a 16-ms peak flux, measured from T0-2 ms, of 8.03(-1.52,+1.61)x10^-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum of the burst (measured from T0 to T0+0.256 s) is best fit in the 20 keV - 4 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.29(-0.14,+0.17), the high energy photon index beta = -3.22(-6.78,+0.76), the peak energy Ep = 936(-162,+161) keV (chi2 = 47/45 dof). All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.