GRB 230827A
GCN Circular 34642
Subject
GRID detection of GRB 230827A
Date
2023-09-08T13:21:40Z (2 years ago)
From
GRID Student Team at Tsinghua University <grid@tsinghua.edu.cn>
Via
Web form
Chenyu Wang and Zirui Yang report on behalf of the GRID Collaboration:
GRID-03B and GRID-04, onboard the same CubeSat, report the detection of the long-duration GRB 230827A, which was also detected by Fermi/GBM, Swift/BAT-GUANO, GRBAlpha, VZLUSAT-2, Glowbug and INTEGRAL/SPI-ACS (GCN 34575, 34582, 34583, 34588, 34603).
The event was triggered with GRID on 2023-08-27 at 18:17:41 UTC. The GRID light curve shows a three-pulse temporal structure. The measured burst duration (T90) in the 30-2000 keV range is approximately 57.8 ± 6.1 seconds.
GRID is a student-led project to monitor the transient gamma-ray sky with multiple detectors onboard different nanosatellites in the era of multi-messenger astronomy. For more information about GRID, please refer to the following references: https://doi.org/10.1007/s10686-019-09636-w and https://doi.org/10.1007/s10686-021-09819-4.
GCN Circular 34603
Subject
GRB 230827A: Glowbug gamma-ray detection
Date
2023-08-30T14:50:54Z (2 years ago)
From
matthew.kerr@gmail.com
Via
Web form
M. Kerr, C.C. Cheung, J. E. Grove, R. Woolf (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge (MSFC), and M.S. Briggs (UAH) report:
The Glowbug [1,2] gamma-ray telescope, operating on the International Space Station, reports the detection of GRB 230827A, which was also detected by Fermi/GBM, GRBAlpha, Swift/BAT-GUANO, VZLUSAT-2, and INTEGRAL/SPI-ACS (GCN 34575, 34583, 34587, 34588).
Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2023-08-27 18:17:50.272 with a duration of 100.4 s and a total significance of about 78.2 sigma. The light curve comprises two broad peaks each of about 50s duration, with the peak flux observed roughly at the center of the first pulse.
Using a standard power-law function with an exponential high-energy cutoff [3] to model the emission over this duration results in a photon index dN/dE~E^x of x=-0.5 and a cutoff energy ("Epeak") of 371 keV. The modeled 10-10000 keV fluence is 2.9e-05 erg/cm^2.
The analysis results presented here are preliminary and use a response function that lacks a detailed characterization of the surrounding passive structure of the ISS.
Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost gamma-ray transient telescopes developed, built, and operated by the U.S. Naval Research Laboratory (NRL) with support from the University of Alabama in Huntsville, USRA, and NASA MSFC. It was launched on 2023 March 15 aboard the Department of Defense Space Test Program’s STP-H9 to the ISS. The detector comprises 12 large-area (15 cm x 15 cm) CsI:Tl panels covering the surface of a half cube, and two hexagonal (5-cm diameter, 10-cm length) CLLB scintillators, giving it a large field of view (instantaneous FoV ~2/3 sky) over a wide energy band of 50 keV to >2 MeV.
[1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959
[2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O
[3] Goldstein, A. et al. 2020, ApJ 895, 40, arXiv :1909.03006
Distribution Statement A: Approved for public release. Distribution is unlimited.
GCN Circular 34594
Subject
GRB 230827A: Fermi GBM Observation
Date
2023-08-29T18:29:51Z (2 years ago)
From
Lorenzo Scotton at UAH <lscottongcn@outlook.com>
Via
Web form
L. Scotton (UAH), C. Fletcher (USRA) and C. Meegan (UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:
"At 18:17:52.93 UT on 27 August 2023, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 230827A (trigger 714853077/230827762).
which was also detected by GRBAlpha (Dafcikova et al. 2023, GCN 34583)
and Swift/BAT GUANO (DeLaunay et al. 2023, GCN 34587).
The Fermi GBM Final Real-time Localization was reported in GCN 34575.
The angle from the Fermi LAT boresight is 95 degrees.
The GBM light curve consists of multiple peaks with a duration (T90)
of about 83 s (50-300 keV). The time-averaged spectrum
from T0-1.2 to T0+85.9 s is best fit by
a power law function with an exponential high-energy cutoff.
The power law index is -0.96 +/- 0.03 and the cutoff energy,
parameterized as Epeak, is 415 +/- 26 keV.
The event fluence (10-1000 keV) in this time interval is
(3.58 +/- 0.08)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+21 s in the 10-1000 keV band is 10.7 +/- 0.4 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/"
GCN Circular 34588
Subject
GRB 230827A: VZLUSAT-2 detection
Date
2023-08-28T20:31:23Z (2 years ago)
From
Marianna Dafčíková at Masaryk University <500025@mail.muni.cz>
Via
Web form
M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk U.), M. Ohno (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), H. Takahashi (Hiroshima U.), F. Munz , M. Topinka, F. Hroch, N. Husarikova, J.-P. Breuer (Masaryk U.), J. Hudec, J. Kapus, M. Frajt, M. Rezenov (Spacemanic s.r.o), R. Laszlo (Needronix), G. Galgoczi (Wigner Research Center/Eotvos U.), N. Uchida (ISAS/JAXA), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), Y. Fukazawa, K. Hirose, H. Matake (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), L. L. Kiss (Konkoly Observatory), T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), K. Torigoe (Hiroshima U.), P. Svoboda, V. Daniel, J. Dudas, M. Junas, J. Gromes (VZLU), I. Vertat (FEL ZCU) -- the VZLUSAT-2/GRB payload collaboration.
The long duration GRB 230827A (Fermi/GBM detection: GCN 34575; GRBAlpha detection: GCN 34583; Swift/BAT-GUANO detection: GCN 34587; INTEGRAL/SPI-ACS detection at 2023-08-27 ~18:17:53 UT) was detected by the GRB detectors on board of the VZLUSAT-2 3U CubeSat (https://www.vzlusat2.cz/en/).
The data acquisition was performed by the GRB detector units no. 0 and no. 1. The detection was confirmed at the peak time 2023-08-27 18:18:09 (18:18:18) UTC. The T90 duration is 82 s (77 s) and the significance during T90 reaches 10 sigma (24 sigma) for detector unit no. 0 (no. 1).
The light curve obtained by VZLUSAT-2 is available here:
https://vzlusat2.konkoly.hu/static/share/GRB230827A_GCN_VZLUSAT2.pdf
All VZLUSAT-2 detections are listed at: https://monoceros.physics.muni.cz/hea/VZLUSAT-2/
The GRB detectors on VZLUSAT-2 are a demonstration payload for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). Two GRB modules of VZLUSAT-2 are placed in a perpendicular manner and each consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~30 keV to ~1000 keV. VZLUSAT-2 was launched on 2022 January 13 from Cape Canaveral.
GCN Circular 34587
Subject
GRB 230827A: Swift/BAT-GUANO detection of a burst outside the coded FOV
Date
2023-08-28T19:25:30Z (2 years ago)
From
Jimmy DeLaunay at University of Alabama <delauj2@gmail.com>
Via
Web form
James DeLaunay (U Alabama), Aaron Tohuvavohu (U Toronto), Samuele Ronchini (PSU), Gayathri Raman (PSU), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC) report:
Swift/BAT did not localize GRB 230827A onboard (T0: 2023-08-27T18:17:52.93 UTC, Fermi trig 714853077)
The Fermi notice, distributed in near real-time, triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1).
Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 90 seconds of BAT event-mode data from [-50,+150] seconds around the time of the burst. All the requested event mode data was delivered to the ground.
The BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu 2022, ApJ, 941, 169), performed on the temporal window [T0-20 s, T0+20 s], detects the burst with a sqrt(TS) of 54.6 in a 8.192 s analysis time bin, starting at T0 + 18.432 s.
NITRATES results are consistent with a burst coming from outside the FOV, with DeltaLLHOut of -61 and are consistent with Fermi GBM's localization (GCN 34575).
See Section 9.1 and Figures 10 and 17 in the NITRATES paper for brief descriptions and interpretation of sqrt(TS), DeltaLLHPeak, and DeltaLLHOut.
GUANO is a fully autonomous, extremely low latency, spacecraft commanding pipeline designed for targeted recovery of BAT event mode data around the times of compelling astrophysical events to enable more sensitive GRB searches.
A live reporting of Swift/BAT event data recovered by GUANO can be found at: https://www.swift.psu.edu/guano/
GCN Circular 34583
Subject
GRB 230827A: GRBAlpha detection
Date
2023-08-28T10:46:50Z (2 years ago)
From
Marianna Dafčíková at Masaryk University <500025@mail.muni.cz>
Via
Web form
M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), N. Husarikova, F. Munz , M. Topinka, M. Kolar, J.-P. Breuer, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal, A. Povalac (Brno U. of Technology), J. Hudec, J. Kapus, M. Frajt (Spacemanic s.r.o), R. Laszlo, M. Koleda (Needronix s.r.o), M. Smelko, P. Hanak, P. Lipovsky (Technical U. of Kosice), G. Galgoczi (Wigner Research Center/Eotvos U.), Y. Uchida, H. Poon, H. Matake (Hiroshima U.), N. Uchida (ISAS/JAXA), T. Bozoki (Eotvos U.), G. Dalya (Eotvos U.), yyT. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), G. Friss (Eotvos U.), Y. Fukazawa, K. Hirose (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), K. Kapas (Eotvos U.), L. L. Kiss (Konkoly Observatory), T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), J. Takatsy (Eotvos U.), K. Torigoe (Hiroshima U.), N. Kogiso, M. Yoneyama (Osaka Metropolitan U.), M. Moritaki (U. Tokyo), T. Kano (U. Michigan) -- the GRBAlpha collaboration.
The long-duration GRB 230827A (Fermi/GBM detection: GCN 34575, INTEGRAL/SPI-ACS detection at 2023-08-27 ~18:17:53 UT) was observed by the GRBAlpha 1U CubeSat (Pal et al. 2023; arXiv:2302.10048).
The detection was confirmed at the peak time 2023-08-27 18:18:14 UTC. The T90 duration measured by GRBAlpha is 73 s and the overall significance during T90 reaches 30 sigma.
The light curve obtained by GRBAlpha is available here:
https://grbalpha.konkoly.hu/static/share/GRB230827A_GCN.pdf
All GRBAlpha detections are listed at: https://monoceros.physics.muni.cz/hea/GRBAlpha/
GRBAlpha, launched on 2021 March 22, is a demonstration mission for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). The detector of GRBAlpha consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~50 keV to ~1000 keV. To increase the duty cycle and the downlink rate, the upgrade of the on-board data acquisition software stack is in progress. The ground segment is also supported by the radio amateur community and it takes advantage of the SatNOGS network for increased data downlink volume.
GCN Circular 34581
Subject
GRB 230827A: BALROG localization (Fermi Trigger / GRB 230827762)
Date
2023-08-27T20:59:21Z (2 years ago)
From
Jochen Greiner at MPE <jcgrog@mpe.mpg.de>
Via
email
B. Biltzinger, T. Preis, J. Burgess & J. Greiner (all MPE Garching) report:
The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger
at 18:17:52 on 27 Aug. 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) = 320.1+/-0.9 deg
Decl.(2000.0) = -20.3+/-0.9 deg
We estimate an additional systematic error of 1 deg.
Further details are available at:
https://grb.mpe.mpg.de/grb/GRB230827762/
The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB230827762/healpix
The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB230827762/json
GCN Circular 34578
Subject
Fermi GRB 230827A: Global MASTER-Net observations report
Date
2023-08-27T19:31:03Z (2 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
Via
legacy email
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-Tavrida robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, SAI Crimea astronomical station) started inspect of the Fermi GRB 230827A ( Fermi GBM team, GCN 34575) errorbox 53 sec after notice time and 86 sec after trigger time at 2023-08-27 18:19:18 UT, with upper limit up to 17.8 mag. The observations began at zenith distance = 74 deg. The sun altitude is -18.8 deg.
MASTER-Kislovodsk robotic telescope located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB 230827A errorbox 61 sec after notice time and 94 sec after trigger time at 2023-08-27 18:19:27 UT, with upper limit up to 17.5 mag. The observations began at zenith distance = 70 deg. The sun altitude is -23.9 deg.
The galactic latitude b = -42 deg., longitude l = 25 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=2261859
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
96 | 2023-08-27 18:19:18 | MASTER-Tavrida | (21h 16m 19.41s , -22d 49m 36.6s) | C | 20 | 13.7 |
104 | 2023-08-27 18:19:27 | MASTER-Kislovodsk | (21h 18m 43.33s , -22d 37m 28.1s) | C | 20 | 15.5 |
104 | 2023-08-27 18:19:27 | MASTER-Kislovodsk | (21h 23m 17.26s , -23d 01m 43.3s) | C | 20 | 14.5 |
127 | 2023-08-27 18:19:49 | MASTER-Tavrida | (21h 05m 33.35s , -22d 39m 05.5s) | C | 20 | 15.1 |
145 | 2023-08-27 18:20:07 | MASTER-Kislovodsk | (21h 18m 38.34s , -22d 38m 28.4s) | C | 20 | 15.5 |
145 | 2023-08-27 18:20:07 | MASTER-Kislovodsk | (21h 23m 12.27s , -23d 02m 45.3s) | C | 20 | 14.6 |
159 | 2023-08-27 18:20:16 | MASTER-Tavrida | (21h 05m 33.35s , -22d 38m 05.6s) | C | 30 | 15.4 |
190 | 2023-08-27 18:20:47 | MASTER-Kislovodsk | (21h 18m 44.53s , -22d 38m 17.4s) | C | 30 | 15.8 |
190 | 2023-08-27 18:20:47 | MASTER-Kislovodsk | (21h 23m 18.58s , -23d 02m 32.4s) | C | 30 | 14.9 |
201 | 2023-08-27 18:20:53 | MASTER-Tavrida | (21h 05m 39.14s , -22d 39m 06.7s) | C | 40 | 15.7 |
245 | 2023-08-27 18:21:37 | MASTER-Kislovodsk | (21h 18m 41.77s , -22d 36m 53.9s) | C | 40 | 15.9 |
245 | 2023-08-27 18:21:37 | MASTER-Kislovodsk | (21h 23m 16.72s , -23d 01m 12.9s) | C | 40 | 14.6 |
311 | 2023-08-27 18:22:38 | MASTER-Kislovodsk | (21h 18m 41.83s , -22d 38m 12.2s) | C | 50 | 16.0 |
311 | 2023-08-27 18:22:38 | MASTER-Kislovodsk | (21h 23m 16.69s , -23d 02m 30.9s) | C | 50 | 14.6 |
391 | 2023-08-27 18:23:48 | MASTER-Kislovodsk | (21h 18m 43.78s , -22d 36m 30.1s) | C | 70 | 16.1 |
391 | 2023-08-27 18:23:48 | MASTER-Kislovodsk | (21h 23m 18.49s , -23d 00m 48.5s) | C | 70 | 14.8 |
663 | 2023-08-27 18:27:55 | MASTER-Kislovodsk | (21h 15m 12.98s , -23d 39m 12.8s) | P- | 120 | 16.5 |
828 | 2023-08-27 18:27:55 | MASTER-Kislovodsk | (21h 15m 12.98s , -23d 39m 12.8s) | P- | 450 | 17.4 | Coadd
663 | 2023-08-27 18:27:55 | MASTER-Kislovodsk | (21h 15m 11.97s , -24d 02m 49.0s) | P| | 120 | 14.2 |
762 | 2023-08-27 18:29:24 | MASTER-Tavrida | (21h 12m 25.92s , -23d 55m 20.9s) | C | 140 | 16.4 |
818 | 2023-08-27 18:30:16 | MASTER-Kislovodsk | (21h 15m 19.41s , -23d 40m 15.8s) | P- | 150 | 16.6 |
818 | 2023-08-27 18:30:16 | MASTER-Kislovodsk | (21h 15m 18.09s , -24d 03m 58.0s) | P| | 150 | 15.0 |
926 | 2023-08-27 18:31:53 | MASTER-Tavrida | (21h 12m 23.87s , -23d 54m 04.8s) | C | 170 | 16.6 |
1109 | 2023-08-27 18:34:51 | MASTER-Tavrida | (21h 12m 23.91s , -23d 55m 43.2s) | C | 180 | 16.6 |
1204 | 2023-08-27 18:36:26 | MASTER-Kislovodsk | (21h 15m 19.86s , -23d 40m 56.0s) | P- | 180 | 16.8 |
1204 | 2023-08-27 18:36:26 | MASTER-Kislovodsk | (21h 15m 19.22s , -24d 04m 35.5s) | P| | 180 | 14.6 |
1297 | 2023-08-27 18:38:00 | MASTER-Tavrida | (21h 12m 26.53s , -23d 53m 56.3s) | C | 180 | 16.9 |
1404 | 2023-08-27 18:39:47 | MASTER-Kislovodsk | (21h 15m 16.77s , -23d 39m 34.8s) | P- | 180 | 16.7 |
1584 | 2023-08-27 18:39:47 | MASTER-Kislovodsk | (21h 15m 16.78s , -23d 39m 34.7s) | P- | 540 | 17.5 | Coadd
1404 | 2023-08-27 18:39:47 | MASTER-Kislovodsk | (21h 15m 15.26s , -24d 03m 02.1s) | P| | 180 | 14.5 |
1484 | 2023-08-27 18:41:06 | MASTER-Tavrida | (21h 12m 21.56s , -23d 54m 47.9s) | C | 180 | 16.9 |
1605 | 2023-08-27 18:43:07 | MASTER-Kislovodsk | (21h 15m 16.92s , -23d 40m 43.4s) | P- | 180 | 16.8 |
1605 | 2023-08-27 18:43:07 | MASTER-Kislovodsk | (21h 15m 16.75s , -24d 04m 26.4s) | P| | 180 | 14.6 |
1670 | 2023-08-27 18:44:12 | MASTER-Tavrida | (21h 12m 21.63s , -23d 53m 47.4s) | C | 180 | 16.9 |
1806 | 2023-08-27 18:46:28 | MASTER-Kislovodsk | (21h 15m 19.31s , -23d 39m 33.5s) | P- | 180 | 16.8 |
1806 | 2023-08-27 18:46:28 | MASTER-Kislovodsk | (21h 15m 18.56s , -24d 03m 08.4s) | P| | 180 | 14.6 |
1858 | 2023-08-27 18:47:20 | MASTER-Tavrida | (21h 12m 26.71s , -23d 54m 47.6s) | C | 180 | 16.9 |
2006 | 2023-08-27 18:49:49 | MASTER-Kislovodsk | (21h 15m 14.52s , -23d 40m 06.2s) | P- | 180 | 16.7 |
2006 | 2023-08-27 18:49:49 | MASTER-Kislovodsk | (21h 15m 13.77s , -24d 03m 41.7s) | P| | 180 | 14.6 |
2046 | 2023-08-27 18:50:28 | MASTER-Tavrida | (21h 12m 20.27s , -23d 55m 45.7s) | C | 180 | 17.2 |
2234 | 2023-08-27 18:53:37 | MASTER-Tavrida | (21h 12m 26.77s , -23d 55m 31.3s) | C | 180 | 17.3 |
2424 | 2023-08-27 18:56:46 | MASTER-Tavrida | (21h 12m 24.32s , -23d 53m 45.3s) | C | 180 | 17.4 |
2612 | 2023-08-27 18:59:54 | MASTER-Tavrida | (21h 12m 24.35s , -23d 55m 37.5s) | C | 180 | 17.3 |
2750 | 2023-08-27 19:02:12 | MASTER-Kislovodsk | (21h 15m 21.73s , -24d 03m 38.2s) | C | 180 | 15.0 |
2750 | 2023-08-27 19:02:12 | MASTER-Kislovodsk | (21h 15m 22.82s , -23d 39m 57.4s) | C | 180 | 13.7 |
2801 | 2023-08-27 19:03:04 | MASTER-Tavrida | (21h 12m 27.29s , -23d 53m 46.8s) | C | 180 | 17.5 |
2950 | 2023-08-27 19:05:33 | MASTER-Kislovodsk | (21h 15m 16.60s , -23d 40m 57.0s) | C | 180 | 15.6 |
2950 | 2023-08-27 19:05:33 | MASTER-Kislovodsk | (21h 15m 16.79s , -24d 04m 42.4s) | C | 180 | 14.7 |
2989 | 2023-08-27 19:06:11 | MASTER-Tavrida | (21h 12m 21.57s , -23d 54m 40.1s) | C | 180 | 17.5 |
3151 | 2023-08-27 19:08:53 | MASTER-Kislovodsk | (21h 22m 53.28s , -23d 47m 21.9s) | C | 180 | 15.8 |
3151 | 2023-08-27 19:08:53 | MASTER-Kislovodsk | (21h 22m 53.30s , -24d 11m 08.0s) | C | 180 | 14.9 |
3179 | 2023-08-27 19:09:22 | MASTER-Tavrida | (21h 12m 22.70s , -23d 53m 39.3s) | C | 180 | 17.5 |
3351 | 2023-08-27 19:12:14 | MASTER-Kislovodsk | (21h 22m 51.42s , -23d 45m 41.3s) | C | 180 | 15.6 |
3352 | 2023-08-27 19:12:14 | MASTER-Kislovodsk | (21h 22m 51.71s , -24d 09m 28.0s) | C | 180 | 14.8 |
3368 | 2023-08-27 19:12:30 | MASTER-Tavrida | (21h 12m 28.11s , -23d 54m 38.6s) | C | 180 | 17.5 |
3552 | 2023-08-27 19:15:34 | MASTER-Kislovodsk | (21h 22m 53.18s , -21d 47m 16.1s) | C | 180 | 15.8 |
3552 | 2023-08-27 19:15:34 | MASTER-Kislovodsk | (21h 22m 53.69s , -22d 10m 54.6s) | C | 180 | 14.7 |
3555 | 2023-08-27 19:15:38 | MASTER-Tavrida | (21h 12m 22.71s , -23d 55m 37.5s) | C | 180 | 17.8 |
3744 | 2023-08-27 19:18:46 | MASTER-Tavrida | (21h 12m 28.12s , -23d 55m 33.6s) | C | 180 | 17.6 |
3933 | 2023-08-27 19:21:55 | MASTER-Tavrida | (21h 12m 24.54s , -23d 53m 59.0s) | C | 180 | 17.7 |
3953 | 2023-08-27 19:22:15 | MASTER-Kislovodsk | (21h 22m 49.92s , -21d 46m 30.2s) | C | 180 | 15.7 |
3953 | 2023-08-27 19:22:15 | MASTER-Kislovodsk | (21h 22m 51.71s , -22d 10m 16.6s) | C | 180 | 14.8 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
GCN Circular 34575
Subject
GRB 230827A: Fermi GBM Final Real-time Localization
Date
2023-08-27T18:28:19Z (2 years ago)
From
Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>
Via
email
The Fermi GBM team reports the detection of a likely LONG GRB
At 18:17:52 UT on 27 Aug 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230827A (trigger 714853077.93055 / 230827762).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 319.1, Dec = -23.9 (J2000 degrees, equivalent to J2000 21h 16m, -23d 53'), with a statistical uncertainty of 1.0 degrees.
The angle from the Fermi LAT boresight is 95.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230827762/quicklook/glg_skymap_all_bn230827762.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/bn230827762/quicklook/glg_healpix_all_bn230827762.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230827762/quicklook/glg_lc_medres34_bn230827762.gif