//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 27344 SUBJECT: GRB 200307A: Fermi GBM Final Real-time Localization DATE: 20/03/07 21:37:14 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely SHORT GRB At 21:26:59 UT on 7 Mar 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200307A (trigger 605309224.181756 / 200307894). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 84.2, Dec = -46.2 (J2000 degrees, equivalent to J2000 05h 36m, -46d 12'), with a statistical uncertainty of 22.5 degrees. The angle from the Fermi LAT boresight is 13.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200307894/quicklook/glg_skymap_all_bn200307894.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/bn200307894/quicklook/glg_healpix_all_bn200307894.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200307894/quicklook/glg_lc_medres34_bn200307894.gif //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 27356 SUBJECT: GRB 200307A: Updated localization from Fermi/GBM and Swift/BAT-GUANO DATE: 20/03/10 20:06:13 GMT FROM: Adam Goldstein at Fermi-GBM, USRA Adam Goldstein (USRA), Aaron Tohuvavohu (U Toronto), Jimmy DeLaunay (Penn State), and Jamie Kennea (Penn State) report on behalf of Fermi/GBM and Swift/BAT: The Fermi/GBM Flight-Position notice, distributed at T0+7 seconds, from the Fermi/GBM detected GRB 200307A (GCN. 27344) triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al. 2020, in prep). Upon trigger by the Fermi notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from [-50,+150] seconds around the time of GRB 200307A. All the requested event mode data was delivered to the ground. In a ground analysis of the event data, we detect GRB 200307A, determine the signal in BAT is of astrophysical origin, and can confidently rule out an origin from inside the contemporaneous BAT field-of-view. At T0, the Earth's position and size relative to Swift were: Earth RA: 30.0439 Earth Dec: 5.2549 Earth Radius: 67.139 deg The Earth, with respect to Swift, occulted over 60% of the Fermi/GBM localization region and can be ruled out for the GRB localization. Fermi GBM provides an updated map by removing the Earth-occulted regions and can be found at the following links: Skymap image: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200307894/quicklook/glg_skymap_all_bn200307894.png HEALPix: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200307894/quicklook/glg_healpix_all_bn200307894.fit The 50% confidence region has decreased from 885 square degrees to 290 square degrees and the 90% confidence region has decreased from 2784 square degrees to 978 square degrees. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 27367 SUBJECT: IPN triangulation of GRB 200307A (short) DATE: 20/03/11 21:19:58 GMT FROM: Anna Ridnaia at Ioffe Institute A. Ridnaia, D. Svinkin, and K. Hurley, on behalf of the IPN, A. Goldstein, M. S. Briggs, and C. Wilson-Hodge on behalf of the Fermi GBM team, A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, and S. Barthelmy, J. Cummings, H. Krimm, and D. Palmer, on behalf of the Swift-BAT team, report: The short-duration GRB 200307A (The Fermi GBM team, GCN Circ. 27344; Goldstein et al., GCN Circ. 27356) was detected by Fermi (GBM trigger 605309224), INTEGRAL (SPI-ACS), and Swift (BAT), at about 77219 s UT (21:26:59). The burst was outside the coded field of view of the BAT. We have triangulated this GRB to a GBM-INTEGRAL annulus centered at RA(2000)=81.577 deg (05h 26m 18s) Dec(2000)=-38.418 deg (-38d 25' 05"), whose radius is 32.263 +/- 3.868 deg (3 sigma). The IPN localization is consistent with, but reduces the area of, the joint Fermi-GBM/Swift-BAT one (GCN Circ. 27356). This localization may be improved. A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB200307_T77219/IPN/