January 2025 - vsnet-grb-info - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-grb-info 37027] Konus-Wind detection of GRB 250118B
by GCN Circulars 23 Jan '25

23 Jan '25

TITLE: GCN CIRCULAR NUMBER: 39019 SUBJECT: Konus-Wind detection of GRB 250118B DATE: 25/01/23 20:34:26 GMT FROM: Anna Ridnaia at Ioffe Institute <ridnaia(a)mail.ioffe.ru> A. Ridnaia, D. Frederiks, A. Lysenko, D. Svinkin, A. Tsvetkova, M. Ulanov, and T. Cline, on behalf of the Konus-Wind team, report: The long-duration GRB 250118B (IPN triangulation: Kozyrev et al., GCN 39017) triggered Konus-Wind at T0=13107.725 s UT (03:38:27.725). The burst light curve shows a multipeaked structure, which starts at ~T0-5.8 s and has a total duration of ~9.4 s. We note a weaker and softer pulse seen in the same KW detector before the main pulse, from ~T0-58.8 s to ~T0-55.9 s. Since this pulse was detected by KW only, its relation to GRB 250118B cannot be currently confirmed. The emission is seen up to ~2 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB250118_T13107/ As observed by Konus-Wind, the burst had a fluence of 3.49(-0.35,+1.30)x10^-6 erg/cm^2 and a 64-ms peak flux, measured from T0-0.244 s, of 2.97(-0.60,+1.22)x10^-6 erg/cm^2/s (both in the 20 keV - 10 MeV energy range). Since a major part of the burst emission was detected before the trigger time, the spectral analysis was performed using the KW 3-channel light curve data. Modelling the KW 3-channel time-integrated spectrum (measured from T0-5.837 s to T0+3.552 s) by a power law with exponential cutoff (CPL) model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep), yields alpha = -1.55(-0.14,+0.18) and Ep = 287(-95,+256) keV. All the quoted errors are estimated at the 68% confidence level. All the presented results are preliminary. View this GCN Circular online at https://gcn.nasa.gov/circulars/39019. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37026] GRB 250121A: Fermi GBM Observation
by GCN Circulars 23 Jan '25

23 Jan '25

TITLE: GCN CIRCULAR NUMBER: 39018 SUBJECT: GRB 250121A: Fermi GBM Observation DATE: 25/01/23 20:33:41 GMT FROM: Matt Godwin <msg0028(a)uah.edu> Matt Godwin (UAH) and C.Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 23:36:05.78 UT on 21 January 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250121A (trigger 759195370/250121983). which was also detected by Fermi-LAT (Holzmann Airasca et al. 2025, GCN 39010). The Fermi GBM on-ground location is consistent with the Fermi-LAT position. (Fermi GBM Team et al. 2025, GCN 39006) The angle from the Fermi LAT boresight is 15 degrees. This burst was also independently detected by INTEGRAL SPI-ACS. The GBM light curve consists of one peak with a duration (T90) of about 5.2 s (50-300 keV). The time-averaged spectrum from T0-0.4 to T0+5.8 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.65 +/- 0.05 and the cutoff energy, parameterized as Epeak, is 230 +/- 10 keV. The event fluence (10-1000 keV) in this time interval is (5.8 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+0.32 s in the 10-1000 keV band is 14.0 +/- 0.3 ph/s/cm^2. A Band function fits the spectrum equally well with Epeak= 210 +/- 20 keV, alpha = -0.59 +/- 0.07 and beta = -2.5 +/- 0.3. 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/" View this GCN Circular online at https://gcn.nasa.gov/circulars/39018. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37025] IPN triangulation of GRB 250118B
by GCN Circulars 23 Jan '25

23 Jan '25

TITLE: GCN CIRCULAR NUMBER: 39017 SUBJECT: IPN triangulation of GRB 250118B DATE: 25/01/23 15:24:56 GMT FROM: Anna Ridnaia at Ioffe Institute <ridnaia(a)mail.ioffe.ru> A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin on behalf of the HEND/Mars Odyssey team, A. Ridnaia, D. Frederiks, A. Lysenko, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, E. Burns on behalf of the IPN, E. Bozzo and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu on behalf of the Swift-BAT 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 long-duration GRB 250118B was detected by Konus-Wind, INTEGRAL (SPI-ACS), Swift (BAT), and Mars-Odyssey (HEND) at about 13107 s UT (03:38:27). The burst was outside the coded field of view of the BAT. We have triangulated it to a preliminary, 3 sigma error box whose coordinates are: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Center: 108.006 (07h 12m 01s) -29.557 (-29d 33' 25") Corners: 114.190 (07h 36m 46s) -29.989 (-29d 59' 21") 112.319 (07h 29m 17s) -30.334 (-30d 20' 03") 101.717 (06h 46m 52s) -28.434 (-28d 26' 02") 103.724 (06h 54m 54s) -28.453 (-28d 27' 11") --------------------------------------------- The error box area is 4.5 sq. deg, and its maximum dimension is 11.0 deg (the minimum one is 28.7 arcmin). The Sun distance was 128 deg. This localization may be improved. A triangulation map and HEALPix FITS file are posted at http://www.ioffe.ru/LEA/GRBs/GRB250118_T13107/IPN/ The HEALPix triangulation map is the multi-order HEALPix in units of probability density. The Konus-Wind time history and spectrum will be given in a forthcoming GCN Circular. View this GCN Circular online at https://gcn.nasa.gov/circulars/39017. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37024] Konus-Wind detection of GRB 250119B
by GCN Circulars 23 Jan '25

23 Jan '25

TITLE: GCN CIRCULAR NUMBER: 39016 SUBJECT: Konus-Wind detection of GRB 250119B DATE: 25/01/23 15:22:17 GMT FROM: Anna Ridnaia at Ioffe Institute <ridnaia(a)mail.ioffe.ru> A. Ridnaia, D. Frederiks, A. Lysenko, D. Svinkin, A. Tsvetkova, M. Ulanov, and T. Cline, on behalf of the Konus-Wind team, report: The long-duration GRB 250119B (Fermi-GBM detection: Fermi GBM team, GCN 38979; Preis et al., GCN 38980; Pathak et al., GCN 39003; INTEGRAL/SPI-ACS detection: Barria et al., GCN 38997; Swift-BAT/GUANO detection: Ronchini et al., 39007 IPN triangulation: Kozyrev et al., GCN 39015) triggered Konus-Wind at T0=30434.631 s UT (08:27:14.631). The burst light curve shows two separated multipeaked emission episodes. The first episode starts at ~T0-18.6 s and has a total duration of ~162 s, the second starts at ~T0+233 s and lasts up to ~T0+274 s. The emission is seen up to ~3 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB250119_T30434/ As observed by Konus-Wind, the burst had a fluence of 1.36(-0.16,+0.16)x10^-4 erg/cm2, and a 64-ms peak flux, measured from T0+31.440 s, of 9.43(-1.10,+1.11)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum of the burst (measured from T0 to T0+273.664 s) is best fit in the 20 keV - 10 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -1.02(-0.08,+0.09), the high energy photon index beta = -2.37(-0.35,+0.19), the peak energy Ep = 332(-36,+43) keV (chi2 = 95/96 dof). The spectrum near the maximum count rate (measured from T0+29.184 to T0+36.096 s) is best fit in the 20 keV - 10 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.64(-0.08,+0.09), the high energy photon index beta = -2.43(-0.17,+0.12), the peak energy Ep = 297(-20,+23) keV (chi2 = 85/79 dof). All the quoted errors are at the 68% confidence level. All the quoted values are preliminary. View this GCN Circular online at https://gcn.nasa.gov/circulars/39016. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37023] IPN triangulation of GRB 250119B
by GCN Circulars 23 Jan '25

23 Jan '25

TITLE: GCN CIRCULAR NUMBER: 39015 SUBJECT: IPN triangulation of GRB 250119B DATE: 25/01/23 15:15:15 GMT FROM: Dmitry Svinkin at Ioffe Institute <svinkin(a)mail.ioffe.ru> A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin on behalf of the HEND/Mars Odyssey team, D. Svinkin, D. Frederiks, A. Lysenko, A. Ridnaia, 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, S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu on behalf of the Swift-BAT 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, long-duration GRB 250119B (Fermi-GBM detection: The Fermi GBM team, GCN 38979; BALROG localization: Preis et al., GCN 38980; INTEGRAL-SPI-ACS detection: Barria et al., GCN 38997; Swift-BAT/GUANO detection: Ronchini et al., 39007) was detected by Fermi (GBM trigger 758968026), Konus-Wind, INTEGRAL (SPI-ACS), Swift (BAT), and Mars-Odyssey (HEND) at about 30421 s UT (08:27:01). The burst was outside the coded field of view of the BAT. We have triangulated it to a preliminary, 3 sigma error box whose coordinates are: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Center: 304.147 (20h 16m 35s) +22.039 (+22d 02' 20") Corners: 308.304 (20h 33m 13s) +21.164 (+21d 09' 51") 307.706 (20h 30m 49s) +21.495 (+21d 29' 42") 299.904 (19h 59m 37s) +22.564 (+22d 33' 49") 300.555 (20h 02m 13s) +22.329 (+22d 19' 46") --------------------------------------------- The error box area is 1.4 sq. deg, and its maximum dimension is 7.9 deg (the minimum one is 11.5 arcmin). The Sun distance was 42 deg. This localization may be improved. The IPN localization is consistent with, but reduces the area of, the Fermi-GBM/RoboBA (GCN 38979), BALROG (GCN 38980), and Swift-BAT/GUANO (GCN 39007) localizations. The burst lightcurve shows two separate emission episodes at ~T0(KW) and at ~T0(KW)+250 s. The IPN localization of the second emission episode is consistent with the first one. A triangulation map and HEALPix FITS file are posted at http://www.ioffe.ru/LEA/GRBs/GRB250119_T30434/IPN The HEALPix triangulation map is the multi-order HEALPix in units of probability density. The Konus-Wind time history and spectrum will be given in a forthcoming GCN Circular. View this GCN Circular online at https://gcn.nasa.gov/circulars/39015. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37022] GRB 250122A: Fermi GBM Final Real-time Localization
by GCN Circulars 22 Jan '25

22 Jan '25

TITLE: GCN CIRCULAR NUMBER: 39014 SUBJECT: GRB 250122A: Fermi GBM Final Real-time Localization DATE: 25/01/22 15:26:00 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply(a)GIOC.nsstc.nasa.gov> The Fermi GBM team reports the detection of a likely LONG GRB At 15:15:21 UT on 22 Jan 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250122A (trigger 759251726.758022 / 250122636). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 266.0, Dec = 24.9 (J2000 degrees, equivalent to J2000 17h 44m, 24d 53'), with a statistical uncertainty of 6.8 degrees. The angle from the Fermi LAT boresight is 87.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250122636/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250122636/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250122636/… View this GCN Circular online at https://gcn.nasa.gov/circulars/39014. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37021] Improved IPN triangulation of GRB 250107C
by GCN Circulars 22 Jan '25

22 Jan '25

TITLE: GCN CIRCULAR NUMBER: 39013 SUBJECT: Improved IPN triangulation of GRB 250107C DATE: 25/01/22 15:22:14 GMT FROM: Dmitry Svinkin at Ioffe Institute <svinkin(a)mail.ioffe.ru> A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin on behalf of the MGNS/BepiColombo and the HEND/Mars-Odyssey teams, J. Benkhoff on behalf of the BepiColombo team, D. Svinkin, D. Frederiks, A. Lysenko, A. Ridnaia, and T. Cline on behalf of the Konus-Wind team, Y. Zhang, C. Wang, S. Xiong, J. Wei, and B. Cordier on behalf of the SVOM-GRM team, A. Goldstein, M. S. Briggs, C. Wilson-Hodge, and E. Burns on behalf of the Fermi GBM team, S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu on behalf of the Swift-BAT 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 long-duration GRB 250107C (SVOM-GRM and GECAM-B detections: Xue et al., GCN 38870; initial IPN triangulation: Svinkin et al., GCN 38879; Konus-Wind detection: Frederiks et al., GCN 38895; CALET-GBM detection: Yoshida et al., GCN 38896) was detected by Konus-Wind, SVOM (GRM), GECAM-B, CALET (GBM), and BepiColombo (MGNS) at about 67936 s UT (18:52:16). We have triangulated it to a preliminary, 3 sigma error box whose coordinates are: ------------------------------- RA(2000), deg Dec(2000), deg ------------------------------- Corners: 348.940 +19.143 344.400 +27.679 344.615 +27.357 348.961 +19.155 ------------------------------- The error box area is 825 sq. arcmin, and its maximum dimension is 10.5 deg (the minimum one is 1.4 arcmin). The Sun distance was 70 deg. This localization may be improved. A triangulation map and HEALPix FITS file are posted at http://www.ioffe.ru/LEA/GRBs/GRB250107_T67934/IPN/ The HEALPix triangulation map is the multi-order HEALPix in units of probability density. View this GCN Circular online at https://gcn.nasa.gov/circulars/39013. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37020] GRB 250114A: Swift-BAT refined analysis
by GCN Circulars 22 Jan '25

22 Jan '25

TITLE: GCN CIRCULAR NUMBER: 39012 SUBJECT: GRB 250114A: Swift-BAT refined analysis DATE: 25/01/22 13:51:00 GMT FROM: Mike Moss at NASA GSFC <mikejmoss3(a)gmail.com> A. Y. Lien (U Tampa), S. D. Barthelmy (GSFC), R. Gupta (GSFC), N. J. Klingler (GSFC/UMBC/CRESSTII), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), C. B. Markwardt (GSFC), M. J. Moss (GSFC), D. M. Palmer (LANL), T. Parsotan (GSFC), D. Sadaula (GSFC/UMBC), T. Sakamoto (AGU) (i.e. the Swift-BAT team): Using the data set from T-239 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 250114A (trigger #1281241) (N. J. Klingler, et al., GCN Circ. 38927). The BAT ground-calculated position is RA, Dec = 166.572, -15.129 deg which is RA(J2000) = 11h 06m 17.3s Dec(J2000) = -15d 07' 44.5" with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment). The partial coding was 21%. The mask-weighted light curves display several pulses between T0 and T0+60 sec. There are also two additional pulses of emission starting around T0+130 and T0+260. T90 (15-350 keV) is 293.89 +- 13.45 sec (estimated error including systematics). The time-averaged spectrum from T-8.528 to T+305.988 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 0.39 +- 0.62, and Epeak of 50.9 +- 6.3 keV (chi squared 44.16 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 3.6 +- 0.3 x 10^-06 erg/cm2 and the 1-sec peak flux measured from T+1.72 sec in the 15-150 keV band is 1.5 +- 0.4 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.84 +- 0.11 (chi squared 66.05 for 57 d.o.f.). All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at https://swift.gsfc.nasa.gov/results/batgrbcat/BAT_refined_circular/1281241 View this GCN Circular online at https://gcn.nasa.gov/circulars/39012. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37019] GRB 250121A: INTEGRAL/SPI-ACS detection
by GCN Circulars 22 Jan '25

22 Jan '25

TITLE: GCN CIRCULAR NUMBER: 39011 SUBJECT: GRB 250121A: INTEGRAL/SPI-ACS detection DATE: 25/01/22 11:04:29 GMT FROM: Aishwarya L Thakur at INAF-IAPS, Rome <aishth(a)outlook.com> Patrizia Barria(a,b), Giulia Gianfagna(a), James Craig Rodi(a), Aishwarya Linesh Thakur(a), Lorenzo Natalucci(a,b), Luigi Piro(a) report: GRB 250121A was discovered by Fermi/GBM (GCN 39006) on 2025-01-21T23:36:05 (UTC). We searched for a corresponding counterpart in the INTEGRAL/SPI-ACS data. In an SPI-ACS light curve above 80 keV, we find a signal temporally coincident with the GBM detection, having an approximate duration of ~ 4 sec. The signal consists of a single pulse over this duration. The approximate peak count rate in SPI-ACS is 74,000 cts/s for E>80 keV, over a median background rate of 62,800 cts/s. This work is based on observations with INTEGRAL, an ESA project with instruments and a science data centre funded by ESA member states (especially the PI countries: Denmark, France, Germany, Italy, Switzerland, and Spain), and with the participation of Russia and the USA. The SPI-ACS detector system has been provided by MPE Garching/Germany. ----- (a) INAF/IAPS-Rome (b) ICSC National Research Centre for High-Performance Computing View this GCN Circular online at https://gcn.nasa.gov/circulars/39011. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37018] GRB 250121A: Fermi-LAT detection
by GCN Circulars 22 Jan '25

22 Jan '25

TITLE: GCN CIRCULAR NUMBER: 39010 SUBJECT: GRB 250121A: Fermi-LAT detection DATE: 25/01/22 10:27:34 GMT FROM: A. Holzmann Airasca at University of Trento and INFN Bari <a.holzmannairasca(a)unitn.it> A. Holzmann Airasca (UniTrento and INFN Bari), D. Depalo (Politecnico and INFN Bari), E. Bissaldi (Politecnico and INFN Bari), R. Gupta (NASA GSFC), C. Bartolini (UniTrento and INFN Bari), S. Lopez (CNRS / IN2P3) on behalf of the Fermi-LAT Collaboration: On January 21, 2025, Fermi-LAT detected high-energy emission from GRB 250121A, which was also detected by Fermi-GBM (trigger 759195370 / 250121983, GCN 39006). The best LAT on-ground location is found to be: RA, Dec = 225.14, -34.37 (J2000) with an error radius of 0.24 deg (90 % containment, statistical error only). This was 15 deg from the LAT boresight at the time of the GBM trigger (T0 = 23:36:05.78 UT). The data from the Fermi-LAT shows a significant increase in the event rate that is spatially and temporally correlated with the GBM emission with high significance. The photon flux above 100 MeV in the time interval 0 - 500 s after the GBM trigger is (2.5 ± 1.2) E-6 ph/cm2/s. The estimated photon index above 100 MeV is 1.7 ± 0.3. The highest-energy photon is a 2.6 GeV event which is observed ~ 15 seconds after the GBM trigger. The Fermi-LAT point of contact for this burst is Aldana Holzmann Airasca (aldana.holzmannairasca(a)ba.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. View this GCN Circular online at https://gcn.nasa.gov/circulars/39010. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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